DOOR Masonite International Corporation

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE

SECURITIES EXCHANGE ACT OF 1934

Filed by the Registrant ☒

Filed by a party other than the Registrant ☐

Check the appropriate box:

MASONITE INTERNATIONAL CORPORATION

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

PRELIMINARY PROXY STATEMENT—SUBJECT TO COMPLETION, DATED MARCH 8, 2024

Masonite International Corporation

1242 East 5^th Avenue

Tampa, Florida 33605

United States

[    ], 2024

Dear Masonite Shareholder:

You are cordially invited to attend a special meeting (including any adjournments or postponements thereof, the “Special Meeting”) of shareholders of Masonite International Corporation, a British Columbia corporation (“Masonite” or the “Company”) to be held on [    ], 2024, at [    ] Eastern time (unless the Special Meeting is adjourned or postponed). We will hold the Special Meeting online via a live webcast at [    ]. To participate in the Special Meeting, you must enter the 16-digit control number included in your proxy card or voting instruction form. Online access to the Special Meeting will open approximately 15 minutes prior to the start of the Special Meeting. You will not be able to attend the Special Meeting in person at a physical location. For purposes of attendance at the Special Meeting, all references in this proxy statement to “present” or “attending” shall mean virtually present at the Special Meeting.

Pursuant to the terms of the Arrangement Agreement, dated as of February 8, 2024 (as may be further amended or supplemented from time to time, the “Arrangement Agreement”), by and among Masonite, Owens Corning, a Delaware corporation (“Owens Corning”), MT Acquisition Co ULC, a British Columbia unlimited liability company and an indirect wholly owned subsidiary of Owens Corning (“Purchaser”), and subject to the terms and conditions set forth therein, Purchaser will acquire all of the issued and outstanding common shares, no par value per share, of Masonite (“Masonite common shares”) at a purchase price of $133.00 per share (the “Per Share Arrangement Consideration”). The acquisition will be completed by way of a statutory, court-approved plan of arrangement (the “Arrangement”) under Division 5 of Part 9 of the Business Corporations Act (British Columbia) (“BCBCA”). Upon completion of the Arrangement, Masonite will be an indirect wholly owned subsidiary of Owens Corning.

At the Special Meeting, you will be asked to consider and vote on (a) a special resolution approving the Arrangement and the related proposals described in Annex B to this proxy statement (the “Arrangement Resolution”), (b) a proposal to approve, on an advisory (non-binding) basis, the compensation that may be paid or become payable to Masonite’s named executive officers that is based on or otherwise related to the Arrangement Agreement and the transactions contemplated by the Arrangement Agreement (the “Compensation Proposal”), and (c) a proposal to adjourn the Special Meeting, if necessary or appropriate, to solicit additional proxies if there are insufficient votes to adopt the Arrangement Agreement at the time of the Special Meeting (the “Adjournment Proposal”).

If the Arrangement is completed, you will be entitled to receive the Per Share Arrangement Consideration, less any applicable withholding taxes, for each Masonite common share you own immediately prior to the completion of the Arrangement (except for Masonite common shares owned by Owens Corning and any of its subsidiaries or Masonite common shares for which dissent rights have been properly exercised pursuant to the BCBCA, the Plan of Arrangement, the interim order of the Supreme Court of British Columbia in respect of the Arrangement and any other order of the Court).

The Board of Directors of Masonite (the “Board of Directors”), after considering the factors more fully described in the enclosed proxy statement, has unanimously: (a) determined that the Arrangement is in the best interest of Masonite and that the consideration to be received by Masonite shareholders pursuant to the Arrangement Agreement is fair, from a financial point of view, to Masonite shareholders, (b) approved the

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Arrangement Agreement, the Plan of Arrangement and the transactions contemplated thereby (including the Arrangement) and determined to recommend approval of the Arrangement Agreement, the Plan of Arrangement and the transactions contemplated thereby (including the Arrangement) to Masonite shareholders, (c) agreed to submit the Arrangement Agreement, the Plan of Arrangement and the Arrangement to Masonite shareholders for approval and to submit the Arrangement to the Supreme Court of British Columbia for approval once the requisite Masonite shareholder approval has been obtained and (d) approved and adopted the execution and delivery of the Arrangement Agreement and the performance by Masonite of its covenants and agreements contained therein and the consummation of the transactions contemplated thereby (including the Arrangement). The Board of Directors unanimously recommends that you vote: (1) “FOR” the Arrangement Resolution; (2) “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

The enclosed proxy statement provides detailed information about the Special Meeting, the Arrangement Agreement and the Arrangement. A copy of the Arrangement Agreement is attached as Annex A to this proxy statement, and a copy of the Plan of Arrangement is attached as Annex C to this proxy statement.

The enclosed proxy statement also describes the actions and determinations of the Board of Directors in connection with its evaluation of the Arrangement Agreement and the Arrangement. You should carefully read and consider the entire enclosed proxy statement and its annexes, including, but not limited to, the Arrangement Agreement and the Plan of Arrangement, as they contain important information about, among other things, the Arrangement and how it affects you.

Whether or not you plan to attend the virtual Special Meeting, please sign, date and return, as promptly as possible, the enclosed proxy card in the accompanying prepaid reply envelope or grant your proxy electronically over the Internet or by telephone (in accordance with the instructions detailed in the section of this proxy statement captioned “The Special Meeting—Voting at the Special Meeting”). If you attend the Special Meeting and vote by ballot, your vote will revoke any proxy that you have previously submitted.

If you hold your shares in “street name,” you should instruct your bank, broker or other nominee how to vote your shares in accordance with the voting instruction form that you will receive from your bank, broker or other nominee. Your bank, broker or other nominee cannot vote on any of the proposals, including the Arrangement Resolution, without your instructions.

Your vote is very important, regardless of the number of shares that you own. We cannot complete the Arrangement unless the proposal to adopt the Arrangement Resolution is approved by the affirmative vote of the holders of at least two-thirds (66²⁄₃%) of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting, assuming a quorum is present.

If you have any questions or need assistance voting your shares, please contact our proxy solicitor:

D.F. King & Co., Inc.

48 Wall Street, 22nd Floor

New York, New York 10005

Bank and Brokers Call Collect: (212) 269-5550

All Others, Please Call Toll-Free: (888) 541-9895

Email: DOOR@dfking.com

On behalf of the Board of Directors, I thank you for your support and appreciate your consideration of these matters.

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Neither the Securities and Exchange Commission nor any state securities regulatory agency has approved or disapproved the Arrangement, passed upon the merits or fairness of the Arrangement or passed upon the adequacy or accuracy of the disclosure contained in the accompanying proxy statement. Any representation to the contrary is a criminal offense.

The accompanying proxy statement is dated [    ], 2024 and, together with the enclosed form of proxy card, is first being mailed to Masonite shareholders on or about [    ], 2024.

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PRELIMINARY PROXY STATEMENT—SUBJECT TO COMPLETION, DATED MARCH 8, 2024

1242 East 5^th Avenue

Tampa, Florida 33605

NOTICE OF SPECIAL MEETING OF SHAREHOLDERS TO BE HELD ON [    ], 2024

NOTICE IS HEREBY GIVEN, in accordance with an interim order (the “Interim Order”) of the Supreme Court of British Columbia (the “Court”) dated [    ], 2024, that a special meeting (the “Special Meeting”) of the holders of common shares, no par value per share, of Masonite International Corporation (“Masonite”) (“Masonite common shares”) will be held on [    ], 2024 at [    ] (Eastern Time) via a live webcast at [     ]. The Special Meeting will be held for the following purposes:

Holders of Masonite common shares (“Masonite shareholders”) at the close of business of [    ], 2024 (the “Record Date”) will be entitled to vote at the Special Meeting. Only Masonite shareholders of record, whose Masonite common shares are registered in their own name as recorded in the registers maintained by Masonite’s transfer agent, American Stock Transfer & Trust Company (each, a “registered Masonite shareholder”), as at the close of business on the Record Date or their duly appointed proxyholders are entitled to receive notice of, attend and vote at the Special Meeting, and any adjournment or postponement of the Special Meeting. If a beneficial owner of Masonite common shares (a “beneficial Masonite shareholder”) wishes to attend and vote at the Special Meeting (or have another attend and vote on the beneficial Masonite shareholder’s behalf), such beneficial Masonite shareholder must complete, sign and return a voting instruction form in accordance with the directions provided.

Pursuant to the BCBCA and the Interim Order, in order for the Arrangement Resolution to become effective, the Arrangement Resolution must be approved by the affirmative vote of the holders of at least two-thirds (66^2/3%) of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting, assuming a quorum is present. Each Masonite common share outstanding on the Record Date of the Special Meeting is entitled to one vote on this proposal.

This Notice of Special Meeting to Masonite shareholders is accompanied by this proxy statement and a proxy card.

A summary of the Arrangement Agreement, dated as of February 8, 2024, by and among Masonite, Owens Corning and MT Acquisition Co ULC (the “Arrangement Agreement”) and the plan of arrangement (the “Plan of

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Arrangement”) is included in this proxy statement, and the full text thereof is attached as Annex A and Annex C, respectively, to this proxy statement and is also available on the Electronic Data Gathering, Analysis, and Retrieval system (“EDGAR”) at www.sec.gov/edgar. The full text of the Interim Order is attached as Annex D to this proxy statement. Masonite shareholders should carefully review and consider all of the information in this proxy statement.

Pursuant to and in accordance with the Interim Order and the provisions of Sections 237 to 247 of the BCBCA (as modified or supplemented by the Interim Order, the Plan of Arrangement and any other order of the Court), registered Masonite shareholders have a right to dissent with respect to the Arrangement Resolution and, if the Arrangement becomes effective, to be paid the fair value of their shares, less any applicable tax withholdings (the “Dissent Rights”). Dissent Rights are more particularly described in this proxy statement. The dissent procedures require that a registered Masonite shareholder who wishes to exercise Dissent Rights send Masonite a written notice to inform Masonite of his, her or its intention to exercise Dissent Rights (the “Dissent Notice”), which notice must be received by Masonite at its office located at 1242 East 5^th Avenue, Tampa, Florida, United States, Attention: Legal Department, with a copy to Masonite’s legal counsel, Cassels Brock & Blackwell LLP, Suite 2200, 885 West Georgia Street, Vancouver, British Columbia, Canada V6C 3E8, Attention: John Christian, not later than 5:00 p.m. (Eastern time) on the day that is two business days immediately preceding the date of the Special Meeting (as it may be adjourned or postponed from time to time). Persons who are beneficial Masonite shareholders who wish to exercise Dissent Rights should be aware that only registered Masonite shareholders are entitled to exercise Dissent Rights. Accordingly, a beneficial Masonite shareholder who desires to exercise Dissent Rights must make arrangements for the Masonite common shares beneficially owned by such holder to be registered in the holder’s name prior to the time the Dissent Notice is required to be received by Masonite or, alternatively, make arrangements for the registered holder of such Masonite common shares to exercise Dissent Rights on the holder’s behalf. It is strongly suggested that any Masonite shareholder wishing to dissent seek independent legal advice, as the failure to comply strictly with the provisions of Sections 237 to 247 of the BCBCA (as modified by the Interim Order, the Plan of Arrangement and any other order of the Court) may result in the loss of all rights thereunder.

If you are a registered Masonite shareholder and are unable to attend the Special Meeting, please complete, date, sign and return the enclosed form of proxy. Instructions on how to complete and return your proxy are included in this proxy statement. Whether or not you expect to attend the Special Meeting, Masonite urges you to submit a proxy to have your shares voted as promptly as possible either: (a) via the Internet at [    ] (see proxy card for instructions); (b) by telephone (see proxy card for instructions); or (c) by completing, signing and returning the enclosed proxy card in the postage-paid envelope provided, so that your shares may be represented and voted at the Special Meeting. If you are a beneficial Masonite shareholder, please follow the instructions on the voting instruction card furnished by your bank, brokerage firm or other nominee that holds your shares. Any Masonite shareholder of record participating in the Special Meeting may vote at the Special Meeting even if such shareholder has returned a proxy card. However, if you are a beneficial Masonite shareholder, you must obtain a “legal proxy” from your bank, brokerage firm, or other nominee that holds your shares to vote at the Special Meeting.

Beneficial Masonite shareholders that receive the Special Meeting materials through their bank, broker or other nominee must complete and return a voting instruction form in accordance with the instructions provided to such beneficial Masonite shareholder by their intermediary to ensure that their Masonite common shares are voted at the Special Meeting in accordance with their instructions. In addition, beneficial Masonite shareholders should contact their intermediary to arrange for such intermediary to complete the necessary transmittal documents (including the Letter of Transmittal) and to ensure that they receive the Per Share Arrangement Consideration for their Masonite common shares through such intermediary if the Arrangement is completed.

Further voting information can be found in this proxy statement.

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A Masonite shareholder that has questions or requires more information with regard to the voting of their Masonite common shares should contact Masonite’s proxy solicitation agent, D.F. King & Co., Inc., by calling toll-free at (888) 541-9895.

DATED as of the    day of [    ], 2024

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YOUR VOTE IS IMPORTANT

WHETHER OR NOT YOU PLAN TO ATTEND THE SPECIAL MEETING, WE ENCOURAGE YOU TO SUBMIT YOUR PROXY AS PROMPTLY AS POSSIBLE: (a) BY TELEPHONE; (b) THROUGH THE INTERNET; OR (c) BY SIGNING AND DATING THE ENCLOSED PROXY CARD AND RETURNING IT IN THE POSTAGE-PAID ENVELOPE PROVIDED. You may revoke your proxy or change your vote at any time before it is voted at the Special Meeting.

If you hold your shares in “street name,” you should instruct your bank, broker or other nominee how to vote your shares in accordance with the voting instruction form that you will receive from your bank, broker or other nominee. Your broker or other agent cannot vote on any of the proposals, including the proposal to adopt the Arrangement Resolution, without your instructions.

If you are a Masonite shareholder of record, voting by ballot at the Special Meeting will revoke any proxy that you previously submitted. If you hold your shares through a bank, broker or other nominee and did not obtain a control number, you must contact your bank, broker or other nominee to obtain a control number in order to vote by ballot at the Special Meeting.

If you fail to (a) return your proxy card, (b) grant your proxy electronically over the Internet or by telephone, or (c) vote by ballot at the Special Meeting, your shares will not be counted for purposes of determining whether a quorum is present at the Special Meeting and, assuming a quorum is present, will have no effect on the Arrangement Resolution, Compensation Proposal, or the Adjournment Proposal.

You should carefully read and consider the entire accompanying proxy statement and its annexes, including, but not limited to, the Arrangement Agreement and Plan of Arrangement, along with all of the documents incorporated by reference into the accompanying proxy statement, as they contain important information about, among other things, the Arrangement and how it affects you. If you have any questions concerning the Arrangement Agreement, the Arrangement, the Special Meeting or the accompanying proxy statement, would like additional copies of the accompanying proxy statement or need help voting your Masonite common shares, please contact our proxy solicitor:

D.F. King & Co., Inc.

48 Wall Street, 22nd Floor

New York, New York 10005

Bank and Brokers Call Collect: (212) 269-5550

All Others, Please Call Toll-Free: (888) 541-9895

Email: DOOR@dfking.com

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TABLE OF CONTENTS

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QUESTIONS AND ANSWERS

The following questions and answers address some commonly asked questions regarding the Arrangement, the Arrangement Agreement, and the Special Meeting. These questions and answers may not address all questions that are important to you. You should carefully read and consider the more detailed information contained elsewhere in this proxy statement and the annexes to this proxy statement, including, but not limited to, the Arrangement Agreement and Plan of Arrangement, along with all of the documents we refer to in this proxy statement, as they contain important information about, among other things, the Arrangement and how it affects you. You may obtain the information incorporated by reference in this proxy statement without charge by following the instructions under the caption “Where You Can Find More Information.”

Q: Why am I receiving these materials?

A: The Board of Directors is furnishing this proxy statement and form of proxy card to Masonite shareholders in connection with the solicitation of proxies to be voted at the Special Meeting.

Q: When and where is the Special Meeting?

A: The Special Meeting is scheduled to be held on [ ], 2024, at [ ] Eastern time at [ ] (unless the Special Meeting is adjourned or postponed). We will hold the Special Meeting online via a live webcast at [ ]. To participate in the Special Meeting, you must enter the 16-digit control number included in your proxy card or voting instruction form. Online access to the Special Meeting will open approximately 15 minutes prior to the start of the Special Meeting. You will not be able to attend the Special Meeting in person at a physical location.

Q: What am I being asked to vote on at the Special Meeting?

A: You are being asked to vote on the following proposals:

Q: Who is entitled to vote at the Special Meeting?

A: Masonite shareholders as of the Record Date are entitled to notice of the Special Meeting and to vote at the Special Meeting. Each holder of Masonite common shares shall be entitled to cast one (1) vote on each matter properly brought before the Special Meeting for each such Masonite common share owned at the close of business on the Record Date.

Q: May I attend and vote at the Special Meeting?

A: Yes. If you are a Masonite shareholder of record, you may attend the Special Meeting on [ ], 2024, at [ ] Eastern time (unless the Special Meeting is adjourned or postponed). If you encounter any difficulties accessing the virtual Special Meeting during the check-in or meeting time, please call the technical support number that will be posted on the virtual Special Meeting log-in page. Technical support will be available starting 15 minutes prior to the Special Meeting. If you have questions about your control number, please contact the bank, broker or other organization that holds your shares. You will not be able to attend the Special Meeting in person at a physical location.

Even if you plan to attend the virtual Special Meeting, to ensure that your shares will be represented at the Special Meeting, we encourage you to sign, date, and return the enclosed proxy card in the accompanying

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prepaid reply envelope or grant your proxy electronically over the Internet or by telephone (in accordance with the instructions detailed in the section of this proxy statement captioned “The Special Meeting—Voting at the Special Meeting”). If you attend the Special Meeting and vote by ballot, your vote will revoke any proxy previously submitted.

If you are a beneficial owner of Masonite common shares, i.e., you hold your shares in “street name,” you should instruct your bank, broker, or other nominee how to vote your shares in accordance with the voting instruction form that you will receive from your bank, broker, or other nominee. Your broker or other agent cannot vote on any of the proposals, including the proposal to adopt the Arrangement Agreement, without your instructions. If you hold your shares in “street name,” and did not obtain a control number, you must contact your bank, broker, or other nominee to obtain a control number to vote your shares by ballot at the Special Meeting.

Q: What is the Arrangement?

A: The Arrangement is the transaction contemplated under the Arrangement Agreement, pursuant to which Purchaser will acquire all of the issued and outstanding Masonite common shares at a purchase price of $133.00 per share, subject to applicable withholding taxes. As a result of the Arrangement, Masonite will become an indirect wholly owned subsidiary of Owens Corning, and Masonite common shares will no longer be publicly traded and will be delisted from the NYSE. In addition, Masonite common shares will be deregistered under the Exchange Act, and Masonite will no longer file periodic reports with the SEC.

The Arrangement will be implemented by way of a Court approved plan of arrangement under Division 5 of Part 9 of the BCBCA pursuant to the terms of the Arrangement Agreement, the Plan of Arrangement, the Interim Order and the Final Order.

The principal features of the Arrangement are summarized under the section of this proxy statement captioned “The Arrangement—Arrangement Steps.”

Q: What will I receive if the Arrangement is completed?

A: Upon completion of the Arrangement, you will be entitled to receive the Per Share Arrangement Consideration, consisting of $133.00 in cash for each Masonite common share that you own immediately prior to the Effective Time (less any applicable withholding taxes), unless you have properly exercised and not withdrawn your Dissent Rights in accordance with the requirements of the BCBCA, the Plan of Arrangement, the Interim Order and any other order of the Court. For example, if you own 100 Masonite common shares, you will receive $13,300.00 in cash, less any applicable withholding taxes.

Q: What are the Canadian federal income tax considerations relating to the Arrangement?

A: This proxy statement contains a general discussion of certain Canadian federal income tax consequences of the Arrangement in the section captioned “The Arrangement—Canadian Federal Income Tax Considerations.” Such a discussion is not intended to be legal or tax advice to any particular Masonite shareholder.

Q: What are the U.S. federal income tax considerations relating to the Arrangement?

A: The exchange of Masonite common shares for cash pursuant to the Arrangement will be a taxable transaction for U.S. federal income tax purposes. Accordingly, a U.S. Holder (as defined under the section of this proxy statement captioned “The Arrangement—U.S. Federal Income Tax Considerations”) who exchanges Masonite common shares for cash pursuant to the Arrangement generally will recognize gain or loss in an amount equal to the difference, if any, between the amount of cash that such U.S. Holder receives pursuant to the Arrangement and such U.S. Holder’s adjusted tax basis in the Masonite common shares surrendered pursuant to the Arrangement by such shareholder.

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For a more complete description of the U.S. federal income tax consequences of the Arrangement, see the section of this proxy statement captioned “The Arrangement—U.S. Federal Income Tax Considerations.” Masonite shareholders should consult their tax advisors regarding the U.S. federal income and other tax consequences relating to the Arrangement in light of their particular circumstances, including the applicability and effect of any state, local, non-U.S. or other tax laws.

Q: What vote is required to approve the Arrangement Resolution, the Compensation Proposal, and the Adjournment Proposal?

A: The affirmative vote of the holders of at least two-thirds (66^2/3%) of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting is required to adopt the Arrangement Resolution, assuming a quorum is present. The affirmative vote of at least a majority of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting is required to approve each of the Compensation Proposal and the Adjournment Proposal, assuming a quorum is present.

If a quorum is present at the Special Meeting, the failure of any shareholder of record to: (a) submit a signed proxy card; (b) grant a proxy over the Internet or by telephone (in accordance with the instructions detailed in the section of this proxy statement captioned “The Special Meeting—Voting at the Special Meeting”); or (c) vote virtually by ballot at the Special Meeting will have, assuming a quorum is present, no effect on the Arrangement Resolution, Compensation Proposal or the Adjournment Proposal. If you hold your shares in “street name” and a quorum is present at the Special Meeting, the failure to instruct your bank, broker or other nominee how to vote your shares will have no effect on the Arrangement Resolution, Compensation Proposal, or the Adjournment Proposal. If a quorum is present at the Special Meeting, each “broker non-vote” will also have no effect on the Arrangement Resolution, the Compensation Proposal or the Adjournment Proposal. If a quorum is present at the Special Meeting, abstentions will also have no effect on the Arrangement Resolution, the Compensation Proposal, and the Adjournment Proposal. If you properly sign your proxy card but do not mark the boxes showing how your shares should be voted on a matter, the shares represented by your properly signed proxy will be voted: (1) “FOR” the Arrangement Resolution; (2) “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

Q: If my shares are held in “street name” by my bank, brokerage firm or other nominee, will my bank, brokerage firm or other nominee vote my shares for me?

A: No. If your shares are held in “street name” by your bank, brokerage firm or other nominee, you must direct your bank, brokerage firm or other nominee on how to vote and you will receive instructions from your bank, brokerage firm or other nominee describing how to vote your Masonite common shares. The availability of Internet or telephonic voting will depend on the nominee’s voting process. Please check with your bank, brokerage firm or other nominee and follow the voting procedures your bank, brokerage firm or other nominee provides.

In accordance with the rules of the NYSE, your bank, brokerage firm or other nominee can vote your Masonite common shares on “routine” matters when they have not received voting instructions from you. However, such banks, brokerage firms and other nominees are precluded from exercising their voting discretion with respect to “non-routine” matters. If you are a beneficial Masonite shareholder and you do not provide these instructions, a “non-vote” occurs with respect to those matters. All proposals to be voted on at the Special Meeting will be considered “non-routine” matters. Accordingly, if you are a beneficial Masonite shareholder and you do not provide your bank, brokerage firm or other nominee instructions on how to vote your Masonite common shares at the Special Meeting, your bank, brokerage firm or other nominee generally will not be permitted to vote your shares on any of the proposals at the Special Meeting. If you are a beneficial Masonite shareholder, Masonite strongly encourages you to provide voting instructions to your bank, brokerage firm or other nominee so that your vote will be counted on all matters.

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A so-called “broker non-vote” results when banks, brokerage firms and other nominees return a valid proxy but do not vote on a particular proposal because they do not have discretionary authority to vote on the matter and have not received specific voting instructions from the beneficial owner of those shares. Broker non-votes count towards a quorum only if at least one proposal is presented with respect to “routine” matters to which the bank, brokerage firm or other nominee has discretionary authority. All proposals to be voted on at the Special Meeting will be “non-routine” matters, and, therefore, broker non-votes, if any, will not be counted as present and entitled to vote for purposes of determining a quorum at the Special Meeting. The effect of not instructing your broker how you wish your shares to be voted will not have an effect on the Arrangement Resolution, the Compensation Proposal or the Adjournment Proposal.

Q: What happens if the Arrangement is not completed?

A: If the Arrangement Resolution is not adopted by shareholders or if the Arrangement is not completed for any other reason, shareholders will not receive any payment for their Masonite common shares. Instead, Masonite will remain an independent public company, Masonite common shares will continue to be listed and traded on the NYSE and registered under the Exchange Act, and we will continue to file periodic reports with the SEC.

Under specified circumstances, Masonite will be required to pay Owens Corning a termination fee of $75 million, upon the termination of the Arrangement Agreement, as described in the section of this proxy statement captioned “The Arrangement Agreement—Termination Fees.”

Q: Why are the shareholders being asked to cast an advisory (non-binding) vote to approve the Compensation Proposal?

A: The Exchange Act and applicable SEC rules thereunder require Masonite to seek an advisory (non-binding) vote with respect to certain payments that could become payable to its named executive officers in connection with the Arrangement.

Q: What will happen if the shareholders do not approve the Compensation Proposal at the Special Meeting?

A: Approval of the Compensation Proposal is not a condition to the completion of the Arrangement. The vote with respect to the Compensation Proposal is an advisory vote and will not be binding on Masonite. Therefore, if the approval of the Arrangement Resolution is obtained and the Arrangement is completed, the amounts payable under the Compensation Proposal will continue to be payable to Masonite’s named executive officers in accordance with the terms and conditions of the applicable agreements.

Q: What do I need to do now?

A: You should carefully read and consider this entire proxy statement and the annexes to this proxy statement, including, but not limited to, the Arrangement Agreement, along with all of the documents that we refer to in this proxy statement, as they contain important information about, among other things, the Arrangement and how it affects you. Then sign, date, and return, as promptly as possible, the enclosed proxy card in the accompanying reply envelope, or grant your proxy electronically over the Internet or by telephone (in accordance with the instructions detailed in the section of this proxy statement captioned “The Special Meeting—Voting at the Special Meeting”), so that your shares can be voted at the Special Meeting, unless you wish to exercise Dissent Rights. If you hold your shares in “street name,” please refer to the voting instruction form provided by your bank, broker or other nominee to vote your shares.

Q: Should I surrender my certificates or book-entry shares now?

A: No. After the Arrangement is completed, Owens Corning will send, or cause the paying agent to send, each holder of record a Letter of Transmittal and written instructions that explain how to exchange Masonite

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common shares represented by such holder’s certificates or book-entry shares for Per Share Arrangement Consideration.

Q: What happens if I sell or otherwise transfer my Masonite common shares after the Record Date but before the Special Meeting?

A: The Record Date for the Special Meeting is earlier than the date of the Special Meeting and the date the Arrangement is expected to be completed. If you sell or transfer your Masonite common shares after the Record Date but before the Special Meeting, unless special arrangements (such as provision of a proxy) are made between you and the person to whom you sell or otherwise transfer your shares and each of you notifies Masonite in writing of such special arrangements, you will transfer the right to receive the Per Share Arrangement Consideration, if the Arrangement is completed, to the person to whom you sell or transfer your shares, but you will retain your right to vote those shares at the Special Meeting. Even if you sell or otherwise transfer your Masonite common shares after the Record Date, we encourage you to sign, date and return the enclosed proxy card in the accompanying reply envelope or grant your proxy electronically over the Internet or by telephone (in accordance with the instructions detailed in the section of this proxy statement captioned “The Special Meeting—Voting at the Special Meeting”).

Q: What is the difference between holding shares as a shareholder of record and as a beneficial owner?

A: If your shares are registered directly in your name with our transfer agent, American Stock Transfer & Trust Company, you are considered, with respect to those shares, to be the “shareholder of record.” In this case, this proxy statement and your proxy card have been sent directly to you by Masonite.

If your shares are held through a bank, broker or other nominee, you are considered the “beneficial owner” of Masonite common shares held in “street name.” In that case, this proxy statement has been forwarded to you by your bank, broker or other nominee who is considered, with respect to those shares, to be the shareholder of record. As the beneficial owner, you have the right to direct your bank, broker or other nominee how to vote your shares by following their instructions for voting. You are also invited to attend the virtual Special Meeting. If you did not obtain a control number you must contact your bank, broker or other nominee to obtain a control number to vote your shares by ballot at the Special Meeting.

Q: How may I vote?

A: If you are a shareholder of record (that is, if your Masonite common shares are registered in your name with American Stock Transfer & Trust Company, our transfer agent), there are four (4) ways to vote:

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If your Masonite common shares are held “in street name” by a bank, broker or other nominee, the holder of your shares will provide you with a copy of this proxy statement, a voting instruction form and directions on how to provide voting instructions. These directions may allow you to vote over the internet or by telephone.

Whether or not you plan to attend the virtual Special Meeting, we urge you to vote in advance by proxy to ensure your vote is counted. We encourage you to submit your proxy over the Internet or by telephone, both of which are convenient, cost-effective, and reliable alternatives to returning a proxy card by mail. You may still attend the virtual Special Meeting and vote by ballot, if you have already voted by proxy.

Please be aware that, although there is no charge for voting your shares, if you vote electronically over the Internet by visiting the address on your proxy card or by telephone by calling the phone number on your proxy card, in each case, you may incur costs such as Internet access and telephone charges for which you will be responsible.

If your shares are held in “street name” through a bank, broker, or other nominee, you may vote through your bank, broker or other nominee by completing and returning the voting instruction form provided by your bank, broker or other nominee, or, if such a service is provided by your bank, broker, or other nominee, electronically over the Internet or by telephone.

Q: If my broker holds my shares in “street name,” will my broker vote my shares for me?

A: No. Your bank, broker or other nominee is permitted to vote your shares on any proposal currently scheduled to be considered at the Special Meeting only if you instruct your bank, broker or other nominee how to vote. You should follow the procedures provided by your bank, broker or other nominee to vote your shares. Without instructions, your shares will not be voted on such proposals, which, assuming a quorum is present, will have no effect on the Arrangement Resolution, the Compensation Proposal, or the Adjournment Proposal.

Q: May I change my vote after I have mailed my signed and dated proxy card?

A: Yes. You can change or revoke your proxy at any time before the final vote at the Special Meeting. If you are the record holder of your shares, you may change or revoke your proxy in any one of three ways:

If you hold your Masonite common shares in “street name,” you should contact your bank, broker or other nominee for instructions regarding how to change your vote. You may also vote by ballot at the Special Meeting by entering the 16-digit control number included in your proxy card. If you have questions about your control number, please contact the bank, broker or other organization that holds your shares. If you did not obtain a control number, you must contact your bank, broker or other nominee to obtain a control number to vote your shares by ballot at the Special Meeting.

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If you have any questions about how to vote or change your vote, you should contact our proxy solicitor:

D.F. King & Co., Inc.

48 Wall Street, 22nd Floor

New York, New York 10005

Bank and Brokers Call Collect: (212) 269-5550

All Others, Please Call Toll-Free: (888) 541-9895

Email: DOOR@dfking.com

Q: What is a proxy?

A: A proxy is your legal designation of another person to vote your Masonite common shares. The written document describing the matters to be considered and voted on at the Special Meeting is called a “proxy statement.” The document used to designate a proxy to vote your Masonite common shares is called a “proxy card.” Howard C. Heckes, our President and Chief Executive Officer, and Russell T. Tiejema, our Chief Financial Officer and Executive Vice President, are the proxy holders for the Special Meeting, with full power of substitution and re-substitution.

Q: If a shareholder gives a proxy, how are the shares voted?

A: Regardless of the method you choose to vote, the individuals named on the enclosed proxy card, or your proxies, will vote your shares in the way that you indicate. When completing the Internet or telephone process or the proxy card, you may specify whether your shares should be voted for or against or to abstain from voting on all, some or none of the specific items of business to come before the Special Meeting.

If you properly sign your proxy card but do not mark the boxes showing how your shares should be voted on a matter, the shares represented by your properly signed proxy will be voted: (1) “FOR” the Arrangement Resolution; (2) “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

Q: What should I do if I receive more than one (1) set of voting materials?

A: This means you own Masonite common shares that are registered under different names or are in more than one account. For example, you may own some shares directly as a shareholder of record and other shares through a broker or you may own shares through more than one broker. In these situations, you will receive multiple sets of proxy materials. You must vote, sign and return all of the proxy cards or follow the instructions for any alternative voting procedure on each of the proxy cards that you receive in order to vote all of the shares you own. Each proxy card you receive comes with its own prepaid return envelope. If you submit your proxy by mail, make sure you return each proxy card in the return envelope that accompanies that proxy card.

Q: Where can I find the voting results of the Special Meeting?

A: Masonite intends to publish final voting results in a Current Report on Form 8-K to be filed with the SEC following the Special Meeting. All reports that Masonite files with the SEC are publicly available when filed. For more information, please follow the instructions in the section of this proxy statement captioned “Where You Can Find More Information.”

Q: When do you expect the Arrangement to be completed?

A: We currently expect to complete the Arrangement in mid-2024. However, the exact timing of completion of the Arrangement cannot be predicted because the Arrangement is subject to the closing conditions specified in the Arrangement Agreement and summarized in this proxy statement, many of which are outside of our control. For more information, please see the section of this proxy statement captioned “The Arrangement Agreement—Conditions to the Arrangement and Expenses.”

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Q: How can I obtain additional information about Masonite?

A: Masonite will provide copies of this proxy statement, documents incorporated by reference, and its 2023 Annual Report, including its Annual Report on Form 10-K for the fiscal year ended January 1, 2024, without charge to any shareholder who makes a written request to our Corporate Secretary at 1242 East 5th Avenue, Tampa, Florida 33605, United States. Masonite’s Annual Report on Form 10-K and other SEC filings may also be accessed at www.sec.gov or on Masonite’s Investor website at https://investor.masonite.com/. Masonite’s website address is provided as an inactive textual reference only. The information provided on or accessible through our website is not part of this proxy statement and is not incorporated in this proxy statement by this or any other reference to our website provided in this proxy statement.

Q: How many copies of this proxy statement and related voting materials should I receive if I share an address with another shareholder?

A: The SEC’s proxy rules permit companies and intermediaries, such as brokers, to satisfy delivery requirements for proxy statements with respect to two or more shareholders sharing the same address by delivering a single proxy statement to those shareholders. This process, which is commonly referred to as “householding,” potentially provides extra convenience for shareholders and cost savings for companies. Masonite and some brokers may be householding our proxy materials by delivering a single set of proxy materials to multiple shareholders who request a copy and share an address, unless contrary instructions have been received from the affected shareholders. If, at any time, you no longer wish to participate in householding and would prefer to receive a separate proxy statement, or if your household is receiving multiple copies of these documents and you wish to request that future deliveries be limited to a single copy, please notify your broker if your shares are held in a brokerage account or Masonite if you are a shareholder of record by sending a written request to our Corporate Secretary at 1242 East 5th Avenue, Tampa, Florida 33605, United States. In addition, Masonite will promptly deliver, upon written or oral request to the address or telephone number above, a separate copy of this proxy statement.

Q: Who can help answer my questions?

A: If you have any questions concerning the Arrangement, the Special Meeting, or the accompanying proxy statement, would like additional copies of the accompanying proxy statement or need help voting your Masonite common shares, please contact our proxy solicitor:

D.F. King & Co., Inc.

48 Wall Street, 22nd Floor

New York, New York 10005

Bank and Brokers Call Collect: (212) 269-5550

All Others, Please Call Toll-Free: (888) 541-9895

Email: DOOR@dfking.com

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FORWARD-LOOKING STATEMENTS

This proxy statement, and any document to which Masonite refers in this proxy statement, contains “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Exchange Act, which are intended to be covered by the safe harbor created by such sections and other applicable laws. These statements do not strictly relate to historical or current results and can be identified by words such as “anticipate,” “appear,” “assume,” “believe,” “estimate,” “expect,” “forecast,” “intend,” “likely,” “may,” “plan,” “project,” “seek,” “should,” “strategy,” “will,” “can,” “could,” “predict,” “future,” “potential,” “intend,” “forecast,” “look,” “build,” “focus,” “create,” “work,” “continue,” “target,” “poised,” “advance,” “drive,” “aim,” “approach,” “seek,” “schedule,” “position,” “pursue,” “progress,” “budget,” “outlook,” “trend,” “guidance,” “commit,” “on track,” “objective,” “goal,” “opportunity,” “ambitions,” “aspire” and variations of negatives of such terms or variations thereof. Other words and terms of similar meaning or import in connection with any discussion of future plans, actions, events or operating, financial or other performance identify forward-looking statements.

Forward-looking statements by their nature address matters that are, to different degrees, uncertain, such as statements regarding the transactions contemplated by the Arrangement Agreement by and among Masonite, Owens Corning, and Purchaser, including the expected time period to consummate the Arrangement, the anticipated benefits (including synergies) of the Arrangement and integration and transition plans, opportunities, anticipated future performance, expected share buyback programs and expected dividends. All such forward-looking statements are based upon current plans, estimates, expectations and ambitions that are subject to risks, uncertainties, assumptions and other factors, many of which are beyond the control of Masonite and Owens Corning, that could cause actual results to differ materially from the results projected in such forward-looking statements. These risks, uncertainties, assumptions and other factors include, without limitation:

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All forward-looking statements in this communication should be considered in the context of the risks and other factors described above and in the specific factors discussed under the heading “Risk Factors” in Masonite’s most recent Annual Report on Form 10-K filed with the SEC, in each case as these risk factors are amended or supplemented by subsequent Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, which will be incorporated by reference into this proxy statement. Masonite’s reports that are filed with the SEC are available on Masonite’s website at https://investor.masonite.com/ and on the SEC’s website at http://www.sec.gov. Any forward-looking statements speak only as of the date the statement is made and Masonite undertakes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. It is not possible to identify all of the risks, uncertainties and other factors that may affect future results. In light of these risks and uncertainties, the forward-looking events and circumstances discussed herein may not occur and actual results may differ materially from those anticipated or implied in the forward-looking statements. Accordingly, readers are cautioned not to place undue reliance on any forward-looking statements.

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THE SPECIAL MEETING

The enclosed proxy is solicited on behalf of the Board of Directors for use at the Special Meeting.

Date, Time and Place

The Special Meeting will be on [ ], 2024, at [ ] Eastern time, and we will hold the Special Meeting virtually via a live webcast at [ ]. To participate in the Special Meeting, you must enter the 16-digit control number included in your proxy card or voting instruction form. Online access to the Special Meeting will open approximately 15 minutes prior to the start of the Special Meeting. If you encounter any difficulties accessing the virtual Special Meeting during the check-in or meeting time, please call the technical support number that will be posted on the virtual Special Meeting log-in page. Technical support will be available starting 15 minutes prior to the Special Meeting. If you have questions about your control number, please contact the bank, broker or other organization that holds your shares. You will not be able to attend the Special Meeting in person at a physical location.

Purpose of the Special Meeting

At the Special Meeting, Masonite shareholders will be asked to vote upon the following proposals:

Only the approval of the Arrangement Resolution is required for completion of the Arrangement. Masonite will transact no other business at the Special Meeting except such business as may properly be brought  before the Special Meeting or any adjournment or postponement thereof.

Record Date; Shares Entitled to Vote; Quorum

Only shareholders of record as of the Record Date are entitled to notice of the Special Meeting and to vote at the Special Meeting. A list of shareholders entitled to vote at the Special Meeting will be available at our principal executive offices located at 1242 East 5th Avenue, Tampa, Florida 33605, United States, during regular business hours for a period of no less than 10 days before the Special Meeting, as well as on the Special Meeting website. The list will also be available electronically during the Special Meeting at [ ] when you enter your 16-digit control number. As of the Record Date, there were [ ] Masonite common shares outstanding and entitled to vote at the Special Meeting.

Subject to the special rights and restrictions attached to the shares of any class or series of shares, 3 persons who are, or who represent by proxy, unrelated shareholders who, in the aggregate, hold at least 15% of the issued shares on the Record Date and that are entitled to be voted at the meeting will constitute a quorum at the Special Meeting. In the event that a quorum is not present at the Special Meeting, it is expected that the Special Meeting will be adjourned to solicit additional proxies.

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Vote Required; Abstentions and Broker Non-Votes

The votes required for each proposal are as follows:

Proposal 1—The Arrangement Resolution: The affirmative vote of holders of at least two-thirds (66^2/3%) of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting is required to approve the Arrangement Resolution, assuming a quorum is present. If a quorum is present at the Special Meeting, abstentions will have no effect on the Arrangement Resolution. For Masonite shareholders who fail to submit a proxy or to vote at the Special Meeting, or fail to instruct their bank, brokerage firm, or other nominee to vote with respect to any proposal, it will have no effect on the Arrangement Resolution, assuming a quorum is present. Adoption of the Arrangement Resolution by Masonite shareholders is a condition to the completion of the Arrangement.

Proposal 2—The Compensation Proposal: The affirmative vote of at least a majority of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting is required to approve, on an advisory (non-binding) basis, the Compensation Proposal, assuming a quorum is present. If a quorum is present at the Special Meeting, abstentions will have no effect on the Compensation Proposal. For Masonite shareholders who fail to submit a proxy or to vote at the Special Meeting, or fail to instruct their bank, brokerage firm, or other nominee to vote with respect to any proposal, it will have no effect on the Compensation Proposal, assuming a quorum is present.

Proposal 3—The Adjournment Proposal: The affirmative vote of at least a majority of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting is required to approve the Adjournment Proposal, assuming a quorum is present. If a quorum is present at the Special Meeting, abstentions will have no effect on the Adjournment Proposal. For Masonite shareholders who fail to submit a proxy or to vote at the Special Meeting, or fail to instruct their bank, brokerage firm, or other nominee to vote with respect to any proposal, it will have no effect on the Adjournment Proposal, assuming a quorum is present.

Each “broker non-vote,” assuming a quorum is present, will have no effect on the Arrangement Resolution, the Compensation Proposal or the Adjournment Proposal. A so-called “broker non-vote” results when banks, brokers and other nominees return a valid proxy voting upon a matter or matters for which the applicable rules provide discretionary authority but do not vote on a particular proposal because they do not have discretionary authority to vote on the matter and have not received specific voting instructions from the beneficial owner of such shares. Masonite does not expect any broker non-votes at the Special Meeting because the rules applicable to banks, brokers and other nominees only provide brokers with discretionary authority to vote on proposals that are considered routine, whereas each of the proposals to be presented at the Special Meeting is considered non-routine. As a result, no broker will be permitted to vote your Masonite common shares at the Special Meeting without receiving instructions. A failure to instruct your broker on how to vote your shares will have no effect on the Arrangement Agreement Proposal, assuming a quorum is present.

Stock Ownership and Interests of Certain Persons

Shares Held by Masonite’s Directors and Executive Officers

As of the Record Date, our executive officers and directors beneficially owned and were entitled to vote, in the aggregate, [ ] Masonite common shares, representing approximately [ ]% of the Masonite common shares outstanding on the Record Date.

We currently expect that our executive officers and directors will vote all of their respective Masonite common shares (1) “FOR” the Arrangement Resolution, (2) “FOR” the Compensation Proposal, and (3) “FOR” the Adjournment Proposal.

Voting at the Special Meeting

If you plan to attend and vote at the virtual Special Meeting, once you attend the Special Meeting, you may use the electronic ballot available on the Special Meeting website in order to vote by ballot. Please note that if

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your Masonite common shares are held by a broker, bank or other nominee, and you wish to vote at the Special Meeting and did not obtain a control number, you must contact your bank, broker or other nominee to obtain a control number to vote your shares by ballot at the Special Meeting.

The virtual Special Meeting will be held on [ ], 2024, at [ ] Eastern time at [ ] (unless the Special Meeting is adjourned or postponed). To participate in the Special Meeting, you must enter the 16-digit control number included in your proxy card or voting instruction form. Online access to the Special Meeting will open approximately 15 minutes prior to the start of the Special Meeting. If you encounter any difficulties accessing the virtual Special Meeting during the check-in or meeting time, please call the technical support number that will be posted on the virtual Special Meeting log-in page. Technical support will be available starting 15 minutes prior to the Special Meeting. If you have questions about your control number, please contact the bank, broker or other organization that holds your shares.

You may also authorize the persons named as proxies on the proxy card to vote your shares by returning the proxy card in advance by mail, through the Internet or by telephone. Although Masonite offers four different voting methods, Masonite encourages you to vote over the Internet or by phone as Masonite believes they are the most cost-effective methods. We also recommend that you vote as soon as possible, even if you are planning to attend the Special Meeting, so that the vote count will not be delayed. Both the Internet and the telephone provide convenient, cost-effective and reliable alternatives to returning your proxy card by mail. If you choose to vote your shares over the Internet or by telephone, there is no need for you to mail back your proxy card.

To Vote Over the Internet:

Vote at [ ] in advance of the Special Meeting. The internet voting system is available 24 hours a day until 11:59 p.m. Eastern time on [ ], 2024. Once you enter the internet voting system, you can record and confirm (or change) your voting instructions. If you have any questions about www.proxyvote.com, please contact the bank, broker, or other organization that holds your shares.

To Vote by Telephone:

Use the telephone number shown on your proxy card. The telephone voting system is available 24 hours a day in the United States until 11:59 p.m. Eastern time on [ ], 2024. Once you enter the telephone voting system, a series of prompts will tell you how to record and confirm (or change) your voting instructions.

To Vote by Proxy Card:

If you received a proxy card, mark your voting instructions on the card and sign, date and return it in the postage-paid envelope provided. For your mailed proxy card to be counted, we must receive it before 9:30 a.m. Eastern time on [ ], 2024.

All shares represented by properly signed and dated proxies received in time for the Special Meeting will be voted at the Special Meeting in accordance with the instructions of the shareholder. Properly signed and dated proxies that do not contain voting instructions will be voted: (1) “FOR” the Arrangement Resolution; (2) “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

If you sign and return your signed proxy card without indicating how you want your Masonite common shares to be voted with regard to a particular proposal, or if you indicate that you wish to vote in favor of the Arrangement Resolution but do not indicate a choice on the Adjournment Proposal or the Compensation Proposal on an non-binding advisory basis, your Masonite common shares will be voted “FOR” each such proposal. Proxy cards that are returned without a signature will not be counted as present at the Special Meeting and cannot be voted.

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If your shares are held in “street name” through a bank, broker or other nominee, you may vote through your bank, broker or other nominee by completing and returning the voting form provided by your bank, broker, or other nominee or attending the Special Meeting and voting using your control number, or, if you did not obtain a control number, contacting your bank, broker, or other nominee to obtain a control number so that you may vote by ballot. If such a service is provided, you may vote over the Internet or telephone through your bank, broker, or other nominee by following the instructions on the voting form provided by your bank, broker, or other nominee. If you do not return your bank’s, broker’s, or other nominee’s voting form, do not vote via the Internet or telephone through your bank, broker, or other nominee, if possible, or do not attend the Special Meeting and vote by ballot, it will not have any effect on the Arrangement Resolution, the Compensation Proposal or the Adjournment Proposal, assuming a quorum is present.

Revocability of Proxies

Any proxy given by a Masonite shareholder may be revoked at any time before it is voted at the Special Meeting by doing any of the following:

If you hold your Masonite common shares in “street name,” you should contact your bank, broker or other nominee for instructions regarding how to change your vote. You may also vote by ballot at the virtual Special Meeting with your control number, or, if you did not obtain a control number, by contacting your bank, broker or other nominee to obtain a control number.

Any adjournment, postponement or other delay of the Special Meeting, including for the purpose of soliciting additional proxies, will allow Masonite shareholders who have already sent in their proxies to revoke them at any time prior to their use at the Special Meeting, as adjourned, postponed, or delayed.

Board of Directors’ Recommendation

The Board of Directors, after considering the factors more fully described in the enclosed proxy statement, has unanimously: (a) determined that the Arrangement is in the best interest of Masonite and that the consideration to be received by Masonite shareholders pursuant to the Arrangement Agreement is fair, from a financial point of view, to Masonite shareholders, (b) approved the Arrangement Agreement, the Plan of Arrangement and the transactions contemplated thereby (including the Arrangement) and determined to recommend approval of the Arrangement Agreement, the Plan of Arrangement and the transactions contemplated thereby (including the Arrangement) to Masonite shareholders, (c) agreed to submit the Arrangement Agreement, the Plan of Arrangement and the Arrangement to Masonite shareholders for approval and to submit the Arrangement to the Supreme Court of British Columbia for approval once the requisite Masonite shareholder approval has been obtained and (d) approved and adopted the execution and delivery of the Arrangement Agreement and the performance by Masonite of its covenants and agreements contained therein and the consummation of the transactions contemplated thereby (including the Arrangement).

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The Board of Directors unanimously recommends that you vote: (1) “FOR” the Arrangement Resolution; (2)  “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

Solicitation of Proxies

The Board of Directors is soliciting your proxy, and Masonite will bear the cost of soliciting proxies. D.F. King & Co., Inc. has been retained to assist with the solicitation of proxies. D.F. King & Co., Inc. will be paid approximately $25,000 and will be reimbursed for its reasonable out-of-pocket expenses for these and other advisory services in connection with the Special Meeting. Solicitation initially will be made by mail and email. Forms of proxies and proxy materials may also be distributed through brokers, custodians and other like parties to the beneficial owners of Masonite common shares, in which case these parties will be reimbursed for their reasonable out-of-pocket expenses. Proxies may also be solicited in person or by telephone, facsimile, electronic mail, or other electronic medium by D.F. King & Co., Inc. or, without additional compensation, by Masonite or Masonite’s directors, officers, and employees.

Anticipated Date of Completion of the Arrangement

Assuming timely satisfaction of necessary closing conditions, including the approval by Masonite shareholders of the proposal to adopt the Arrangement Resolution, we currently anticipate that the Arrangement will be consummated in mid-2024.

Delisting and Deregistration of Masonite Common Shares

If the Arrangement is completed, the Masonite common shares will be delisted from the NYSE and deregistered under the Exchange Act, and Masonite common shares will no longer be publicly traded.

Other Matters

At this time, we know of no other matters to be voted on at the Special Meeting. If any other matters properly come before the Special Meeting, your Masonite common shares will be voted in accordance with the discretion of the appointed proxy holders.

Householding of Special Meeting Materials

The SEC has adopted rules that permit companies and intermediaries, such as brokers and banks, to satisfy the delivery requirements for proxy statements with respect to two or more shareholders sharing an address by delivering a single proxy statement, as applicable, addressed to those shareholders, unless contrary instructions have been received. This procedure, which is commonly referred to as “householding,” reduces the amount of duplicate information that shareholders receive and lowers printing and mailing costs for companies.

Certain brokerage firms may have instituted householding for beneficial owners of Masonite common shares held through brokerage firms. If your family has multiple accounts holding Masonite common shares, you may have already received a householding notification from your broker. You may decide at any time to revoke your decision to household, and thereby receive multiple copies of proxy materials. If you wish to opt out of this procedure and receive a separate set of proxy materials in the future, or if you are receiving multiple copies and would like to receive only one, you should contact your broker, trustee or other nominee or Masonite at the address and telephone number below. A separate copy of these proxy materials will be promptly delivered upon request by writing to: 1242 East 5th Avenue, Tampa, Florida 33605, United States, Attention: Corporate Secretary.

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Questions and Additional Information

If you have any questions concerning the Arrangement, the Special Meeting or this proxy statement, would like additional copies of this proxy statement or need help voting your Masonite common shares, please contact our proxy solicitor:

D.F. King & Co., Inc.

48 Wall Street, 22nd Floor

New York, New York 10005

Bank and Brokers Call Collect: (212) 269-5550

All Others, Please Call Toll-Free: (888) 541-9895

Email: DOOR@dfking.com

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PROPOSAL 1: THE ARRANGEMENT RESOLUTION

Overview

Masonite is asking its shareholders to approve the Arrangement Resolution, a copy of which is attached as Annex B to this proxy statement. For a summary and detailed information regarding this proposal, see the information about the Arrangement Agreement and the Arrangement throughout this proxy statement, including the information in the sections of this proxy statement captioned “Proposal 1: The Arrangement Resolution,” “The Arrangement,” and “The Arrangement Agreement.” Copies of the Arrangement Agreement and the Plan of Arrangement are attached as Annex A and Annex C, respectively, to this proxy statement. We urge you to read the full text of the Arrangement Agreement and Plan of Arrangement.

Vote Required for Approval

Pursuant to the BCBCA and the Interim Order, in order for the Arrangement Resolution to become effective, the Arrangement Resolution must be approved by the affirmative vote of at least two-thirds (66 ^2/3%) of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting, assuming a quorum is present. Each Masonite common share outstanding on the record date of the Special Meeting is entitled to one vote on this proposal. If a quorum is present at the Special Meeting, failures to vote, abstentions and broker non-votes will have no effect on the vote for this proposal.

Recommendation of the Board of Directors

The Board of Directors unanimously recommends that Masonite shareholders vote “FOR” the Arrangement Resolution.

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THE ARRANGEMENT

This section of the proxy statement describes the material aspects of the Arrangement. This discussion of the Arrangement is qualified in its entirety by reference to the Arrangement Agreement and the Plan of Arrangement, which are attached to this proxy statement as Annex A and Annex C, respectively, and incorporated into this proxy statement by reference. You should carefully read and consider the entire Arrangement Agreement and Plan of Arrangement, which are the legal documents that govern the Arrangement, because these documents contain important information about the Arrangement and how it affects you. Additionally, see the section of this proxy statement captioned “The Arrangement Agreement” for additional and more detailed information regarding the legal documents that govern the Arrangement, including the conditions to completion of the Arrangement and the provisions for terminating or amending the Arrangement Agreement. In addition, important information about Masonite is included in or incorporated by reference into this proxy statement. See the section titled “Where You Can Find More Information.”

Parties Involved in the Arrangement

Masonite International Corporation

1242 East 5th Avenue

Tampa, Florida 33605, United States

Masonite International Corporation, a British Columbia corporation, is a global designer, manufacturer, marketer and distributor of interior and exterior doors and door systems. Masonite common shares trade on the NYSE under the symbol “DOOR.” The principal executive offices of Masonite are located at 2771 Rutherford Road, Concord, Ontario L4K 2N6, Canada, and its telephone number is (800) 895-2723.

Owens Corning

One Owens Corning Parkway

Toledo, Ohio 43659, United States

Owens Corning, a Delaware corporation, is a global building and construction materials leader committed to building a sustainable future through material innovation. Its roofing products and systems enhance curb appeal of people’s homes and protect residential and commercial buildings. Its insulation products conserve energy and improve acoustics, fire resistance and air quality in the spaces where people live, work and play. Its fiberglass composites make thousands of products lighter, stronger and more durable. Owens Corning’s common stock trades on the NYSE under the symbol “OC.” The principal executive offices of Owens Corning are located at One Owens Corning Parkway, Toledo, Ohio 43659, and its telephone number is (419) 248-8000.

MT Acquisition Co ULC

One Owens Corning Parkway

Toledo, Ohio 43659, United States

MT Acquisition Co ULC was incorporated under the BCBCA as a limited liability company on January 31, 2024. The Purchaser is an indirect wholly owned subsidiary of Owens Corning formed solely for the purpose of engaging in the transactions contemplated by the Arrangement Agreement. The principal business address of Purchaser is c/o Owens Corning, One Owens Corning Parkway, Toledo, Ohio 43659.

Effect of the Arrangement

Upon the terms and subject to the conditions of the Arrangement Agreement, Purchaser will acquire all of the issued and outstanding Masonite common shares in exchange for the Per Share Arrangement Consideration, being $133.00 in cash per share. As a result of the Arrangement, Masonite will become an indirect wholly owned subsidiary of Owens Corning, and Masonite common shares will no longer be publicly traded and will be delisted from the NYSE. In addition, Masonite common shares will be deregistered under the Exchange Act, and Masonite will no longer file periodic reports with the SEC. If the Arrangement is completed, you will not own any shares of the capital stock of Purchaser or Owens Corning. The Arrangement will be implemented by way of a court approved plan of arrangement under Division 5 of Part 9 of the BCBCA pursuant to the terms of the Arrangement Agreement.

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For information regarding when the Effective Time will occur, see the section of this proxy statement captioned “The Arrangement—Closing and Effective Time.”

Effect on Masonite If the Arrangement Is Not Completed

If the Arrangement Agreement is not adopted by Masonite shareholders, or if the Arrangement is not completed for any other reason:

Arrangement Steps

The following summarizes the steps that will occur under the Plan of Arrangement on the Effective Date, if all conditions to the completion of the Arrangement have been satisfied or waived. The following description is qualified in its entirety by reference to the full text of the Plan of Arrangement attached as Annex C to this proxy statement.

Pursuant to the Plan of Arrangement, commencing at the Effective Time, the following events or transactions shall occur, and be deemed to have occurred and be taken and effected, in the following order, without any further act or formality required on the part of any person, except as may be expressly provided in the Plan of Arrangement, in each case, unless stated otherwise, effective as at one minute intervals starting at the Effective Time:

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Required Shareholder Approval

At the Special Meeting, Masonite shareholders will be asked to consider and, if deemed advisable, pass the Arrangement Resolution, the full text of which is attached as Annex B to this proxy statement, to approve the Arrangement.

To be effective, the Arrangement Resolution must be approved by the affirmative vote of the holders of at least two-thirds (66^2/3%) of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting, assuming a quorum is present. Each Masonite common share outstanding on the record date of the Special Meeting is entitled to one vote on this proposal.

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If the resolution approving the Arrangement does not receive the requisite approval, the Arrangement will not be completed. See the section captioned “Dissent Rights” in this proxy statement for information concerning the rights of registered Masonite shareholders to dissent in respect of the Arrangement Resolution.

Required Court Approval

The Arrangement requires approval by the Court under the BCBCA. On [ ], 2024, Masonite obtained the Interim Order providing for the calling, holding and conducting of the Special Meeting and other procedural matters. Copies of the Interim Order and the Notice of Hearing of Petition are attached as Annex D and Annex H, respectively, to this proxy statement.

If the Arrangement Resolution is approved at the Special Meeting, Masonite will apply for the Final Order. Subject to the foregoing, the Court hearing in respect of the Final Order is scheduled to take place at 9:45 a.m. (Pacific Time) on [ ], 2024, or as soon thereafter as the hearing of the Final Order can be heard or at such other date and time as the Court may direct, at the Supreme Court of British Columbia, located at 800 Smithe Street, Vancouver, British Columbia, V6Z 2E1.

At the Court hearing, Masonite shareholders and Incentive Security Holders (as such term is defined in the Interim Order) who wish to participate or to be represented or to present evidence or argument may do so, subject to the rules of the Court, the Interim Order and any further order of the Court. Although the authority of the Court is very broad under the BCBCA, the Court will consider, among other things, the fairness of the terms and conditions of the Arrangement, both from a substantive and procedural point of view, and the rights and interests of every affected party. The Court may approve the Arrangement as proposed or as amended in any manner the Court may direct. The Court’s approval is required for the Arrangement to become effective.

Under the terms of the Interim Order, any Masonite shareholder and Incentive Security Holder has the right to appear (either in person or by counsel) and make submissions at the hearing of the application for the Final Order. Any party desiring to appear at the hearing of the application for the Final Order is required to file with the Court and deliver to Masonite’s legal counsel at the address set out below, by or before 4:00 p.m. (Pacific Time) on [ ], 2024, a response to petition (a “Response to Petition”) and a copy of all materials upon which they intend to rely. If the hearing is postponed, adjourned or rescheduled then, subject to further direction of the Court, only those parties having previously served a Response to Petition in compliance with the Interim Order will be given notice of the new date.

The Response to Petition and supporting materials must be delivered, within the time specified, to Masonite’s legal counsel at the following address:

Cassels Brock and Blackwell LLP

885 West Georgia Street

Vancouver, British Columbia

V6C 3E8

Attention: Raj Mittal

Parties who wish to participate in or be represented at the Court hearing should consult their legal advisors as to the necessary requirements.

Arrangement Consideration

Masonite Common Shares

At the Effective Time, each Masonite common share issued and outstanding immediately prior to the Effective Time (other than Masonite common shares held by dissenting Masonite shareholders in respect of

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which Dissent Rights have been duly and validly exercised, Masonite or any of its subsidiaries, Purchaser, or Owens Corning or any of its subsidiaries) will be deemed to be assigned and transferred by the holder thereof to Purchaser in exchange for the Per Share Arrangement Consideration, being $133.00 in cash, and (a) each registered holder of such Masonite common share shall cease to be the registered holder thereof and to have any rights as a Masonite shareholder other than the right to be paid the Per Share Arrangement Consideration, (b) the name of each such registered holder shall be removed from the register of Masonite shareholders maintained by or on behalf of Masonite, and (c) Purchaser shall be deemed to be the transferee of such Masonite common shares free and clear of all liens and shall be entered in the register of Masonite shareholders maintained by or on behalf of Masonite.

After the Arrangement is completed, you will have the right to receive the Per Share Arrangement Consideration in respect of each Masonite common share that you own immediately prior to the Effective Time (less any applicable withholding taxes), but you will no longer have any rights as a shareholder (except that shareholders who properly exercise their Dissent Rights will have a right to receive payment of the “fair value” of their shares as determined pursuant to a dissent proceeding, as contemplated by British Columbia law). For more information, see the section of this proxy statement captioned “Dissent Rights.”

Treatment of Masonite Equity Awards

Each Masonite RSU Award and each Masonite PRSU Award that is held by an employee and does not vest on or prior to the Effective Time by its terms will be exchanged at the Effective Time for a time-vesting Owens Corning RSU Award subject to substantially the same terms and conditions as applied to the corresponding Masonite RSU Award or Masonite PRSU Award immediately prior to the Effective Time, with the number of shares of Owens Corning common stock underlying such Owens Corning RSU Award equal to the product, rounded to the nearest whole share, obtained by multiplying (a) the number of Masonite common shares underlying the Masonite RSU Award or Masonite PRSU Award immediately prior to the Effective Time by (b) the Equity Award Exchange Ratio. All Masonite RSU Awards and Masonite PRSU Awards that vest on or prior to the Effective Time or are held by an individual who is not an employee will be canceled at the Effective Time in exchange for the Per Share Arrangement Consideration in respect of each share of Masonite common stock subject to such Masonite RSU Award or Masonite PRSU Award. All Masonite RSU Awards held by non-employee directors will be canceled at the Effective Time in exchange for the Per Share Arrangement Consideration in respect of each Masonite common share subject to such Masonite RSU Award.

The number of Masonite common shares subject to Masonite PRSU Awards will be determined (a) with respect to performance periods that are complete as of the Effective Time, based on actual performance, and (b) with respect to performance periods that are incomplete as of the Effective Time, with performance goals deemed achieved at 122% of the target level (or, in the case of Masonite PRSU Awards that do not have a target level, such performance goals will be deemed fully satisfied).

Each Masonite SAR Award will be canceled at the Effective Time in exchange for a cash payment in respect of each share of Masonite common stock subject to such Masonite SAR Award equal to the excess (if any) of the Per Share Arrangement Consideration over the applicable exercise price.

Treatment of the Masonite ESPP

Pursuant to the Arrangement Agreement, the Board of Directors (or a duly authorized committee thereof) will adopt resolutions and take all other actions as may be required to provide that (a) no new participants will commence participation in the Masonite ESPP after February 8, 2024, (b) no participant will be allowed to increase his or her payroll contribution rate in effect as of February 8, 2024 or make separate non-payroll contributions on or following February 8, 2024, and (c) no new offering period or purchase period will commence or be extended pursuant to the Masonite ESPP, in each case, after February 8, 2024. If the Effective Time is expected to occur prior to the end of the current purchase period, Masonite will take action to provide for

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the Early Exercise ESPP Date. The Early Exercise ESPP Date will be as close to the Effective Time as is administratively practicable. The Masonite ESPP will terminate, in accordance with its terms, no later than immediately prior to and effective as of the Effective Time (but subject to the consummation of the Arrangement).

Background of the Arrangement

The following chronology summarizes the key meetings and events that led to the signing of the Arrangement Agreement. This chronology does not purport to catalogue every conversation of or among the Board of Directors, Masonite’s management and Masonite’s financial and legal advisors, Owens Corning or any other person.

As part of Masonite’s ongoing consideration and evaluation of its long-term strategic goals and plans, the Board of Directors and Masonite’s senior management regularly reviews, considers and assesses Masonite’s historical performance, future growth prospects and strategic plan and considers various strategic opportunities available to Masonite as well as ways to enhance shareholder value and Masonite’s performance and prospects, taking into account various factors, including the business, competitive, regulatory, financing and economic environment and developments in Masonite’s industry. These reviews have included discussions as to whether Masonite should continue to execute on its strategy as a standalone company, optimize its capital structure, pursue a sale of the company or other potential opportunities for business combinations, acquisitions and other financial and strategic alternatives. As part of these reviews, the Board of Directors, together with Masonite’s management and with the assistance of Masonite’s advisors, considered from time to time the best potential avenue to enhance shareholder value along with the potential benefits and risks of potential alternatives. The Board of Directors and management also regularly engage with Masonite’s shareholders to discuss and solicit their perspectives on Masonite’s strategic and financial direction. To assist in these evaluations, at various times during 2023 and 2024, Masonite consulted with Goldman Sachs & Co. LLC (“Goldman Sachs”) and Jefferies LLC (“Jefferies”), its financial advisors, and other strategic advisors from time to time, as well as with Wachtell, Lipton, Rosen & Katz (“Wachtell Lipton”), its legal advisor, and Cassels Brock & Blackwell LLP (“Cassels”), its British Columbia, Canada legal advisor.

In February 2023, Brian Chambers, Board Chair, President and Chief Executive Officer of Owens Corning, contacted Howard C. Heckes, President and Chief Executive Officer of Masonite, to offer an introductory meeting in Tampa, Florida.

On February 28, 2023, Mr. Heckes met socially in Tampa, Florida, with Mr. Chambers. There was no discussion of a potential business combination between the two companies at that time.

On May 10, 2023, Mr. Chambers contacted Mr. Heckes to schedule a call. Mr. Heckes informed Robert J. Byrne, Chairman of the Board of Directors, of the request.

On May 10 and 11, 2023, at a regularly scheduled meeting of the Board of Directors, Mr. Heckes briefed the Board of Directors on his interactions with Mr. Chambers to date.

On May 12, 2023, Mr. Chambers expressed on a call with Mr. Heckes his interest in meeting in person to discuss a potential business combination between the two companies. Mr. Heckes expressed to Mr. Chambers that Masonite was comfortable with its standalone plan and was focused on executing it. Mr. Heckes reported his conversation with Mr. Chambers to Mr. Byrne.

On May 18, 2023, Mr. Chambers indicated on a call with Mr. Heckes that Owens Corning was interested in a potential transaction with Masonite and asked to meet with Mr. Heckes in person to discuss Owens Corning’s perspectives on the topic. Mr. Heckes reported his conversation with Mr. Chambers to Mr. Byrne.

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On June 5, 2023, Mr. Heckes met with Mr. Chambers in Tampa, Florida, during which Mr. Chambers expressed Owens Corning’s interest in pursuing a business combination between the two companies. During the meeting, Mr. Chambers provided an overview of Owens Corning’s preliminary, non-binding proposal. During the meeting, Owens Corning delivered to Masonite a letter setting forth a preliminary, non-binding proposal to acquire all of the outstanding Masonite common shares for $120.00 in cash per share (the “First OC Proposal”). The closing price of Masonite common shares on June 2, 2023 was $94.76 per share. In addition, the letter stated that Owens Corning had several specific due diligence requests and required a limited number of targeted meetings with key personnel in order to complete its due diligence, and requested a period of exclusivity to complete the required due diligence and finalize definitive transaction documents in a quick and efficient manner. Exclusivity was not subsequently granted. Also on June 5, 2023, Mr. Heckes forwarded the First OC Proposal to Mr. Byrne and updated him on the discussion with Mr. Chambers.

On June 9, 2023, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and representatives of Wachtell Lipton present. During the meeting, Mr. Heckes provided an update to the Board of Directors regarding his discussions with Mr. Chambers since the May 10-11, 2023 Board of Directors meeting. Mr. Heckes and the Board of Directors also reviewed the terms proposed in the First OC Proposal. Mr. Heckes then explained the steps Masonite had taken since the receipt of the First OC Proposal, including discussions with Wachtell Lipton and meetings with several potential financial advisors to assist Masonite in evaluating and responding to the First OC Proposal. Mr. Heckes reviewed certain considerations for facilitating an efficient process for Masonite and the Board of Directors to evaluate the First OC Proposal, and recommended that certain directors serve in an advisory capacity to the senior management team in between meetings of the full Board of Directors for, among other things, considering retention of experienced financial advisors, analyzing the First OC Proposal and preparing materials and analysis to assist the full Board of Directors in evaluating and responding to the First OC Proposal. After discussion, the Board of Directors decided that each of the following directors would serve in such advisory role: Messrs. Heckes, Byrne, Jonathan F. Foster, Francis M. Scricco and Ms. Jody L. Bilney (collectively, the “Advisory Group”). The Board of Directors then engaged in a discussion of considerations relating to the timing of a response to Owens Corning. It was noted that the Board of Directors would require updated financial projections in order to evaluate the First OC Proposal. Mr. Heckes then discussed with the Board of Directors the initial response proposed to be sent to Owens Corning while Masonite and its senior management and outside advisors proceeded with the work required for the Board of Directors to consider and respond to the First OC Proposal. The directors concurred with providing an initial response to Owens Corning early in the following week, which would indicate that Masonite was evaluating the First OC Proposal and would respond when it was ready to do so.

On June 11, 2023, the Advisory Group held a meeting by videoconference with members of Masonite’s senior management and representatives of Wachtell Lipton to consider next steps. Mr. Heckes and Russell T. Tiejema, Masonite’s EVP and Chief Financial Officer, provided an update regarding their discussions with potential financial advisors to assist Masonite in evaluating and responding to the First OC Proposal. In light of various factors, including experience, reputation, knowledge and expertise regarding similar strategic situations and the industry in which Masonite operates, and conversations with representatives of each of the financial advisors, Messrs. Heckes and Tiejema recommended selecting Goldman Sachs to serve as financial advisor in connection with the potential transaction with Owens Corning. After discussion, the Advisory Group concurred with the recommendation of Messrs. Heckes and Tiejema to retain Goldman Sachs, which was approved by the Board of Directors at a subsequent meeting. Masonite subsequently entered into a formal engagement letter with Goldman Sachs.

On June 12, 2023, representatives of Masonite sent a written response to representatives of Owens Corning indicating Masonite was in the process of evaluating the First OC Proposal and would respond once it was ready to do so.

On June 13, 2023, Mr. Chambers contacted Mr. Heckes and inquired about the timeline for Masonite’s response to the First OC Proposal and the process for evaluation of the First OC Proposal (including hiring of advisors). Mr. Heckes restated the response set forth in the letter sent the prior day.

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On June 27, 2023, Goldman Sachs sent to Masonite a customary disclosure letter in respect of certain relationships between Goldman Sachs and Owens Corning during the prior two-year period.

On June 29, 2023, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and representatives of each of Wachtell Lipton, Cassels and Goldman Sachs. During the meeting, Cassels provided the Board of Directors with an overview of the Board of Directors’ fiduciary duties under British Columbia law. Next, the Board of Directors reviewed the financial projections that had been prepared by Masonite’s management. Representatives of Goldman Sachs reviewed with the Board of Directors its preliminary financial analyses, including based on management’s financial projections, and answered questions from the directors regarding the preliminary financial analyses. The Board of Directors discussed with Masonite’s management and its advisors a range of potential responses to Owens Corning regarding the First OC Proposal and related considerations, including whether or not to engage in any further discussions with Owens Corning. After discussion, members of the Board of Directors directed management to update the financial projections to reflect certain growth initiatives and additional opportunities, as contemplated by the management standalone plan, in order for the Board of Directors to better understand the potential impact of these initiatives and opportunities on the projections and related financial analyses.

On July 6, 2023, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and representatives of each of Wachtell Lipton, Cassels, and Goldman Sachs. During the meeting, the Board of Directors reviewed the financial projections that had been prepared by Masonite’s management, reflecting feedback received at the June 29, 2023 meeting of the Board of Directors. Representatives of Goldman Sachs reviewed with the Board of Directors its updated preliminary financial analyses, including based on management’s financial projections, and answered questions from the directors regarding the updated preliminary financial analyses. After discussion, the Board of Directors determined that the First OC Proposal undervalued Masonite and authorized Masonite’s management to reject the First OC Proposal. The Board of Directors noted that if Owens Corning wished to present a higher proposal, the Board of Directors would meet again with management and advisors to consider it.

On July 7, 2023, Masonite sent Owens Corning a letter indicating that Masonite was not interested in engaging in further discussions based on the First OC Proposal.

On July 13, 2023, Mr. Chambers contacted Mr. Heckes and expressed the strategic importance to Owens Corning of a potential transaction between the two companies.

Later on the same day, Owens Corning delivered another letter to Masonite, setting forth a revised, non-binding proposal to acquire all of the outstanding Masonite common shares for $128.00 in cash per share (the “Second OC Proposal”). The closing price of Masonite common shares on July 12, 2023 was $101.40 per share. The Second OC Proposal restated Owens Corning’s due diligence requirements and request for exclusivity. Exclusivity was not subsequently granted. Mr. Heckes shared the Second OC Proposal with Mr. Byrne and updated him on the discussion with Mr. Chambers on the same date. The Second OC Proposal was made available to the Board of Directors later that day.

On July 14, 2023, the Board of Directors held a meeting by videoconference, with members of Masonite’s senior management and representatives of Wachtell Lipton and Goldman Sachs. Mr. Heckes, the Board of Directors and the advisors reviewed the Second OC Proposal, and Mr. Heckes noted that Mr. Chambers requested access to certain non-public information about Masonite’s business strategy, financial projections and growth initiatives and additional opportunities, among other things, to determine whether Owens Corning would be able to propose a higher price. Mr. Heckes noted that Mr. Chambers emphasized that the Second OC Proposal was based solely on publicly available information and that Mr. Chambers expected it would be sufficient to open a dialogue that would allow Owens Corning to better understand Masonite’s standalone plan and determine whether it might be able to increase its proposed purchase price. Mr. Heckes also updated the Board of Directors about Masonite’s upcoming earnings release for the second quarter of 2023 and provided certain other business

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updates, including regarding the current competitive landscape. The Board of Directors discussed with Masonite’s management and advisors a range of potential responses to the Second OC Proposal and related considerations. After discussion, members of the Board of Directors determined that the Second OC Proposal continued to undervalue Masonite, but the Board of Directors agreed that it would be in the best interest of Masonite and its shareholders to share certain strategic and financial information with Owens Corning, subject to a confidentiality agreement, to enable Owens Corning to better understand Masonite’s intrinsic value and growth initiatives and potentially make a proposal providing greater value than the Second OC Proposal. The Board of Directors directed Masonite’s management to coordinate with Wachtell Lipton about communicating this message to Owens Corning and providing a draft of a confidentiality agreement that would include a standstill.

On July 18, 2023, Mr. Heckes contacted Mr. Chambers and expressed the Board’s view that the Second OC Proposal continued to undervalue Masonite but that Masonite would agree to share certain limited financial and strategic due diligence information to enable Owens Corning to determine if it could make a proposal that provided more value, subject to Owens Corning entering into a customary confidentiality agreement with a standstill. Following the call, Mr. Heckes sent a draft confidentiality agreement to Mr. Chambers that included an 18-month standstill with a customary fallaway provision.

On July 19, 2023, Masonite and Owens Corning entered into a confidentiality agreement, which included Masonite’s proposed standstill and fallaway provision. Over the course of the next several weeks, representatives of Owens Corning and its advisors conducted due diligence focused on Masonite’s business strategy, financial projections and growth initiatives and additional opportunities, and, as part of such due diligence, members of Masonite’s management engaged in due diligence calls and virtual meetings with, and responded to written due diligence requests from, representatives of Owens Corning. Representatives of Goldman Sachs also attended these calls and virtual meetings.

On July 21, 2023, Mr. Chambers contacted Mr. Heckes and provided a letter regarding a planned August 11, 2023 meeting in Tampa and reattaching Owens Corning’s due diligence requests.

On July 28, 2023 and on August 1, 2023, Mr. Heckes and Mr. Chambers exchanged emails during which they finalized the details of a meeting in Tampa on August 11, 2023, including the topics to be covered and who the attendees would be from both companies.

Throughout August and September 2023, Owens Corning conducted due diligence through calls, virtual meetings, certain written questions and answers and a virtual dataroom, which was first made available to representatives of Owens Corning and their advisors on August 2, 2023.

On August 2, 2023, representatives of Masonite provided to representatives of Owens Corning an updated financial model consistent with the discussion of the Board of Directors on July 6, 2023.

On August 11, 2023, certain members of Masonite and Owens Corning’s management teams and representatives of Goldman Sachs and Owens Corning’s financial advisor, Morgan Stanley & Co. LLC (“Morgan Stanley”), met in person in Tampa, Florida, to discuss, among other things, (a) Mr. Heckes’ vision for Masonite’s growth opportunities and initiatives, and other business, pricing and marketing strategies, (b) Masonite’s innovation pipeline and strategy, and (c) areas of Owens Corning’s due diligence review.

On September 22, 2023, Mr. Chambers contacted Mr. Heckes to reaffirm Owens Corning’s interest in pursuing a transaction. Later that day, Mr. Heckes and Mr. Chambers had a call during which Mr. Chambers stated that Owens Corning would deliver a revised proposal.

On September 25, 2023, Owens Corning delivered a letter to Masonite, setting forth a revised, non-binding proposal to acquire all of the outstanding Masonite common shares for $132.00 in cash per share (the “Third OC Proposal”). The closing price of Masonite common shares on September 22, 2023 was $93.09 per share. In

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addition, the letter stated that Owens Corning had only limited confirmatory due diligence outstanding and was ready to progress quickly towards entering into a definitive transaction agreement no later than Masonite’s third quarter of 2023 earnings announcement, estimated to be during the week of November 6, 2023. Owens Corning again requested a period of exclusivity to complete confirmatory due diligence and finalize definitive transaction documents. Exclusivity was not subsequently granted. Also on September 25, 2023, Mr. Heckes forwarded the Third OC Proposal to Mr. Byrne and updated him on the discussion with Mr. Chambers on the same date. The Third OC Proposal was made available to the Board of Directors later that day.

On October 2, 2023, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and representatives of Wachtell Lipton and Goldman Sachs to review the terms proposed in the Third OC Proposal. During the meeting, the Board of Directors reviewed the updated financial projections that had been prepared by Masonite’s management as part of Masonite’s annual strategic planning process based on management’s updated predictions and expectations of Masonite’s financial performance during the relevant periods, reflecting, among other things, the current and expected competitive landscape and industry conditions, which were expected to negatively impact certain aspects of Masonite’s near-term performance and positively impact certain aspects of Masonite’s long-term performance, including updated underlying assumptions. Representatives of Goldman Sachs reviewed with the Board of Directors its updated preliminary financial analyses, including based on management’s updated financial projections, and answered questions from the directors regarding the updated preliminary financial analyses. The Board of Directors discussed with Masonite’s management and advisors a range of potential responses to Owens Corning regarding the Third OC Proposal and related considerations. After discussion, members of the Board of Directors determined that the Third OC Proposal continued to undervalue Masonite, but that management should communicate to Owens Corning that the Board of Directors would consider engaging in a transaction at a purchase price of no less than $140.00 per share. The Board of Directors directed Masonite’s management to coordinate with representatives of Goldman Sachs and Wachtell Lipton regarding delivery of that message to Owens Corning.

On October 3, 2023, Mr. Heckes contacted Mr. Chambers and informed him of the Board of Directors’ view that the Third OC Proposal continued to undervalue Masonite, taking into account the updated financial projections reviewed with the Board of Directors the prior day, but that Masonite would be willing to consider engaging in a transaction at a price no less than $140.00 per share. Mr. Heckes and Mr. Chambers also discussed certain considerations relating to Masonite’s financial analysis and management’s updated financial projections and underlying assumptions, including relating to growth initiatives and additional opportunities, and Mr. Heckes explained how it supported a price of at least $140.00 per share.

On October 5, 2023, representatives of Masonite provided to representatives of Owens Corning an updated financial model consistent with the discussion of the Board of Directors on October 2, 2024.

On October 17, 2023, Mr. Chambers contacted Mr. Heckes and indicated that Naren Srinivasan, SVP, Strategy and Corporate Development at Owens Corning, would contact Mr. Tiejema to further discuss Masonite’s financial outlook.

On October 27, 2023, Mr. Tiejema and Mr. Srinivasan held a meeting by videoconference. During the meeting, Mr. Tiejema discussed, among other things, Masonite’s current business environment and resulting negative revisions to Masonite’s 2023 and 2024 financial outlook.

On November 17, 2023, Mr. Chambers contacted Mr. Heckes and requested a call. Later that day, Mr. Chambers and Mr. Heckes had a call during which Mr. Chambers requested an in-person meeting for Mr. Chambers to better understand Masonite’s financial projections. Also on November 17, 2023, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and representatives of Wachtell Lipton. During the meeting, among other discussion topics, Mr. Heckes updated the Board of Directors regarding his discussions with Mr. Chambers the prior day. Mr. Heckes stated he would update the Board of Directors following the in-person meeting with Mr. Chambers. Next, representatives of

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Jefferies joined the meeting and attended in Jefferies’ capacity as Masonite’s financial advisors for the proposed acquisition of PGT Innovations Inc. (“PGTI” and, such transaction, the “PGTI Transaction”). Representatives of Jefferies updated the Board of Directors on matters relating to the PGTI Transaction.

On November 20, 2023, Mr. Heckes and Mr. Chambers met in Tampa, Florida, and Mr. Chambers delivered a letter containing a revised proposal to acquire all of the outstanding Masonite common shares for $120.00 in cash per share (the “Fourth OC Proposal”). The closing price of Masonite common shares on November 17, 2023 was $87.98 per share. Mr. Chambers noted that the revised purchase price reflected Masonite’s reduced projected 2024 adjusted EBITDA, headwinds in the end markets for Masonite products, expected volume share loss, reduced expected EBITDA margins in the short term, investor reaction to Masonite’s recent Investor Day, analyst consensus regarding Masonite’s share price and other macro headwinds.

On November 21, 2023, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and Wachtell Lipton. During the meeting, Mr. Heckes provided the Board of Directors with an update regarding his discussion with Mr. Chambers in connection with the Fourth OC Proposal and explained the reasoning Mr. Chambers conveyed the prior day regarding the revised purchase price reflected in the Fourth OC Proposal. Next, Mr. Heckes and the Board of Directors reviewed the terms proposed in the Fourth OC Proposal, and Mr. Heckes answered questions from the directors regarding the Fourth OC Proposal. The Board of Directors discussed with Masonite’s management and Wachtell Lipton a range of potential responses to Owens Corning regarding the Fourth OC Proposal and related considerations. After discussion, the Board of Directors determined, in light of Owens Corning’s reduced offer price and Masonite’s potential transaction with PGTI, not to engage in further discussions with Owens Corning and to pursue the PGTI Transaction.

On December 18, 2023, Masonite announced its entry into a definitive agreement relating to the PGTI Transaction, pursuant to which PGTI shareholders would receive $41.00 per each PGTI share they own, comprised of $33.50 in cash and $7.50 in Masonite common shares.

On January 2, 2024, PGTI announced that MITER Brands provided to PGTI an unsolicited proposal to acquire PGTI for $41.50 per each PGTI share in cash.

On January 3, 2024, Mr. Chambers called Mr. Heckes to reiterate Owens Corning’s continued interest in pursuing an acquisition of Masonite. Later that day, Owens Corning delivered another letter to Masonite proposing to acquire all of the outstanding Masonite common shares for $132.00 in cash per share should the PGTI Transaction be terminated (the “Fifth OC Proposal”). The closing price of Masonite common shares on January 2, 2024 was $84.99 per share. Also on January 3, 2024, Mr. Heckes forwarded the Fifth OC Proposal to Mr. Byrne and updated him on the discussion with Mr. Chambers on the same date. The Fifth OC Proposal was made available to the Board of Directors later that day.

On or about January 4, 2024, Masonite’s management informed Jefferies of the Fifth OC Proposal and the prior OC proposals in order for Jefferies to assist Masonite on potential next steps for both the PGTI Transaction and the potential transaction with Owens Corning. Masonite subsequently entered into a formal engagement letter with Jefferies in connection with the potential transaction with Owens Corning.

On January 13, 2024, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and representatives of Wachtell Lipton, Goldman Sachs and Jefferies. During the meeting, Mr. Heckes and the Board of Directors reviewed the terms proposed in the Fifth OC Proposal, including in the context of the status of the pending PGTI Transaction. Mr. Heckes noted that while the PGTI Transaction was pending, the Board of Directors was unable to accept the Fifth OC Proposal given that the terms of the Fifth OC Proposal assumed termination of the PGTI Transaction. Next, representatives of Goldman Sachs also provided an update on a call with Morgan Stanley, noting that Morgan Stanley and Owens Corning believed due diligence and negotiation of definitive transaction agreements could be completed within 7-10 days. The Board of Directors discussed with Masonite’s management and advisors the potential benefits and risks of engaging

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further with Owens Corning based on the Fifth OC Proposal, taking into account that the PGTI Transaction was pending. Although there was no ability to enter into a transaction with Owens Corning while the PGTI Transaction was pending, the Board of Directors instructed Masonite’s management and representatives of Goldman Sachs to update the financial analyses utilizing Masonite’s management’s current financial projections for purposes of presenting such financial analyses to the Board of Directors at the following meeting in connection with its consideration of a potential response to Owens Corning, taking into account at such time the status of the PGTI Transaction. The Board of Directors also determined that, if the PGTI Transaction were terminated, the risks of contacting other parties to gauge their interest in a potential transaction with Masonite outweighed the potential benefits of such outreach at such time.

On January 17, 2024, Masonite announced the termination of the PGTI Transaction after the Board of Directors determined not to offer a revised price in response to the “topping” bid that PGTI had received from MITER Brands. Upon termination of the PGTI Transaction, Masonite received a breakup fee of $84 million.

Later on January 17, 2024, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and representatives of Wachtell Lipton, Goldman Sachs and Jefferies. During the meeting, the Board of Directors reviewed updated financial projections that had been prepared by Masonite’s management as part of Masonite’s annual strategic planning process based on expectations of Masonite’s financial performance during the relevant periods (the “Management Projections,” as described further in the section of this proxy statement captioned “The Arrangement—Management Projections”). The Management Projections reflected the current and expected competitive landscape and industry conditions and opportunities and risks inherent in Masonite’s standalone plan, including updated underlying assumptions. Representatives of Goldman Sachs reviewed with the Board of Directors its updated preliminary financial analyses, including based on the Management Projections. Jefferies also reviewed its preliminary financial analyses, including based on the Management Projections, and discussed with the Board of Directors certain sensitivities to Masonite’s standalone plan reflecting less optimistic operating assumptions of Masonite’s management. Goldman Sachs and Jefferies answered questions from the directors regarding their respective preliminary financial analyses. The Board of Directors discussed with Masonite’s management and Masonite’s advisors a range of potential responses to Owens Corning regarding the Fifth OC Proposal and related considerations. After discussion, the Board of Directors directed Masonite’s management to inform Owens Corning that Masonite was willing to engage in a confirmatory due diligence process and with negotiation of definitive transaction documents, with the understanding that further negotiation of price and terms would be required. On January 22, 2024, representatives of Davis Polk, Owens Corning’s legal advisor, provided a draft Arrangement Agreement to representatives of Wachtell Lipton.

Between January 17 and 31, 2024, representatives of Masonite, Wachtell Lipton and Goldman Sachs had numerous conversations with representatives of Owens Corning and its advisors expressing that $132.00 in cash per share would not be a sufficient price for the Board of Directors to approve a transaction with Owens Corning.

On January 25 and 26, 2024, representatives of Owens Corning conducted in-person site visits at Masonite’s sites in (a) Pittsburg, Kansas, (b) Laurel, Mississippi, and (c) Mesquite, Texas.

On January 28, 2024, representatives of Wachtell Lipton provided a mark-up of the draft Arrangement Agreement to representatives of Davis Polk. The mark-up of the draft Arrangement Agreement proposed, among other things, (a) a “Company Termination Fee” equal to 2% of the equity value of Masonite in the transaction payable by Masonite in the event the Arrangement Agreement was terminated under certain circumstances, (b) a newly added “Parent Termination Fee” equal to 9% of the equity value of Masonite payable by Owens Corning in the event the Arrangement Agreement was terminated under certain circumstances relating to the failure to obtain required regulatory approvals, and (c) an outside date of 12 months with up to two additional three-month extensions. The mark-up also proposed that unvested equity incentive awards held by employees be cashed out at the closing of the Arrangement.

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On January 29 and 30, 2024, representatives of Masonite had due diligence calls with representatives of Owens Corning and, during the months of January and February 2024, representatives of Masonite continued to respond to written due diligence requests from representatives of Owens Corning.

On January 31, 2024, representatives of Davis Polk provided a revised draft Arrangement Agreement to representatives of Wachtell Lipton. The revised draft Arrangement Agreement proposed, among other things, a “Company Termination Fee” equal to 2.5% of the equity value of Masonite and a “Parent Termination Fee” equal to 5% of the equity value of Masonite. The revised draft Arrangement Agreement also included proposed interim operating covenants related to a Canadian tax matter that could impact Owens Corning post-closing. On the same day, Mr. Chambers informed Mr. Heckes that Owens Corning would increase its proposal to $133.00 in cash per share, subject to certain terms, including that the “Company Termination Fee” would equal to 2.5% of the equity value of Masonite and the “Parent Termination Fee” would equal to 5% of the equity value of Masonite, and the rolling over of unvested equity incentive awards held by Masonite’s employees.

On February 1, 2024, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and representatives of Wachtell Lipton, Goldman Sachs and Jefferies. During the meeting, Mr. Heckes provided an update to the Board of Directors regarding the status of the due diligence and negotiation process with Owens Corning. Mr. Heckes explained that as part of the price discussions, Owens Corning stated that it had identified several negative drivers to value that were partially offset by the breakup fee Masonite received from PGTI. Mr. Heckes noted that following further negotiations, Owens Corning had increased its proposed price to $133.00 in cash per share, subject to final approval by Owens Corning’s board of directors and resolution of the Canadian tax matter. Next, representatives from Wachtell Lipton reviewed with the Board of Directors the key terms of the proposed Arrangement Agreement, and answered questions from the directors regarding, among other things, the terms and conditions relating to executive compensation and benefits matters and other matters in the Arrangement Agreement and the Canadian tax matter. Representatives of Masonite’s management then provided the Board of Directors with an update regarding the communication and roll out plan in connection with an announcement of the potential transaction with Owens Corning.

Between February 2 and February 8, 2024, members of Masonite’s management, with the assistance of representatives of Wachtell Lipton and/or Cassels, and Owens Corning’s management, with the assistance of representatives of Davis Polk and/or Stikeman Elliott LLP, Owens Corning’s Canadian legal advisor, negotiated the terms of the Arrangement Agreement and related documentation, including the interim operating covenants relating to the Canadian tax matter.

On February 4, 2024, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and representatives of Wachtell Lipton, Cassels, Goldman Sachs and Jefferies. During the meeting, Mr. Heckes provided an update to the Board of Directors regarding the remaining open matters in the due diligence and negotiation process with Owens Corning, including with respect to the Canadian tax matter. Next, Goldman Sachs and Jefferies reviewed with the Board of Directors their respective preliminary financial analyses, based on the Management Projections. As part of this discussion, the Board of Directors and representatives of Goldman Sachs also discussed a set of projections, which was provided by Masonite’s management in addition to the Management Projections and reflected certain less optimistic assumptions and risks inherent in the Management Projections (i.e., a downward sensitivity case). Goldman Sachs and Jefferies answered questions from the directors regarding their respective preliminary financial analyses. Representatives from Wachtell Lipton then noted there were no meaningful changes to the proposed key terms of the Arrangement Agreement since last presented to the Board of Directors on January 17, 2024 other than certain executive compensation and employee-related matters that were explained by Mr. Heckes. Representatives from Cassels next reviewed with the Board of Directors its fiduciary duties in connection with its consideration of the potential transaction with Owens Corning. Mr. Heckes then provided the Board of Directors with an update regarding the updated communication and roll out plan in connection with an announcement of the potential transaction with Owens Corning.

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On February 8, 2024, the Board of Directors held a meeting by videoconference with members of Masonite’s senior management and representatives of Wachtell Lipton, Goldman Sachs and Jefferies. During the meeting, Mr. Heckes informed the Board of Directors that there were no changes to the key terms of the transaction since the last meeting of the Board of Directors on February 4, 2024 and that Owens Corning had resolved the Canadian tax matter discussed at prior meetings. Goldman Sachs and Jefferies noted for the Board of Directors that there were no material changes to their respective financial analyses, which had been updated and provided to the Board of Directors in advance of this meeting, from the prior Board of Directors meeting on February 4, 2024. In advance of this meeting, Goldman Sachs also provided an updated disclosure letter in respect of certain relationships between Goldman Sachs and Owens Corning during the prior two-year period, and Jefferies provided certain information regarding Jefferies’ material investment banking relationships with Masonite and Owens Corning during the prior two-year period. Goldman Sachs then rendered Goldman Sachs’ oral opinion to the Board of Directors (which was subsequently confirmed in writing by delivery of Goldman Sachs’ written opinion dated February 8, 2024) that, as of the date of the opinion and based on and subject to the various assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken as described in the opinion, the $133.00 per share cash consideration to be paid to the holders (other than Owens Corning and its affiliates) of common shares, no par value, of Masonite pursuant to the Arrangement Agreement was fair from a financial point of view to such holders. Jefferies then rendered its oral opinion to the Board of Directors (confirmed by delivery of a written opinion dated February 8, 2024) to the effect that, as of the date of the opinion and based on and subject to the various assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken as described in the opinion, the $133.00 per share cash consideration to be received in the Arrangement by holders of Masonite common shares (other than, as applicable, Owens Corning, Purchaser and their respective affiliates) pursuant to the Arrangement Agreement was fair, from a financial point of view, to such holders. Following further discussion, the Board of Directors (a) determined that the Arrangement is in the best interest of Masonite and that the consideration to be received by Masonite shareholders pursuant to the Arrangement Agreement is fair, from a financial point of view, to Masonite shareholders, (b) approved the Arrangement Agreement, the Plan of Arrangement and the transactions contemplated thereby (including the Arrangement) and unanimously determined to recommend approval of the Arrangement Agreement, the Plan of Arrangement and the transactions contemplated thereby (including the Arrangement) to Masonite shareholders, (c) agreed to submit the Arrangement Agreement, the Plan of Arrangement and the Arrangement to Masonite shareholders for approval and to submit the Arrangement to the Supreme Court of British Columbia for approval once the requisite Masonite shareholder approval has been obtained, and (d) approved and adopted the execution and delivery of the Arrangement Agreement and the performance by Masonite of its covenants and agreements contained therein and the consummation of the transactions contemplated thereby (including the Arrangement).

Later that day, Masonite, Owens Corning and Purchaser executed the Arrangement Agreement.

On February 9, 2024, Masonite issued a press release announcing the execution of the Arrangement Agreement.

Recommendation of the Board of Directors and Reasons for the Arrangement

Recommendation of the Board of Directors

The Board of Directors has unanimously: (a) determined that the Arrangement is in the best interest of Masonite and that the consideration to be received by Masonite shareholders pursuant to the Arrangement Agreement is fair, from a financial point of view, to Masonite shareholders, (b) approved the Arrangement Agreement, the Plan of Arrangement and the transactions contemplated thereby (including the Arrangement) and determined to recommend approval of the Arrangement Agreement, the Plan of Arrangement and the transactions contemplated thereby (including the Arrangement) to Masonite shareholders, (c) agreed to submit the Arrangement Agreement, the Plan of Arrangement and the Arrangement to Masonite shareholders for approval and to submit the Arrangement to the Supreme Court of British Columbia for approval once the requisite Masonite shareholder approval has been

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obtained, and (d) approved and adopted the execution and delivery of the Arrangement Agreement and the performance by Masonite of its covenants and agreements contained therein and the consummation of the transactions contemplated thereby (including the Arrangement).

The Board of Directors unanimously recommends that you vote: (1) “FOR” the Arrangement Resolution; (2) “FOR” the Compensation Proposal; and (3) “FOR” the Adjournment Proposal.

Reasons for the Arrangement

In the course of evaluating the Arrangement, the Board of Directors consulted with Masonite’s management, Wachtell Lipton, Cassels, Goldman Sachs and Jefferies. In reaching its determination and recommendation, the Board of Directors considered a number of factors, including those below (which are not listed in any relative order of importance), all of which it viewed as generally supporting its (a) approval of the execution and delivery of the Arrangement Agreement by Masonite, the performance by Masonite of its covenants and other obligations under the Arrangement Agreement, and the consummation of the Arrangement upon the terms and subject to the conditions set forth in the Arrangement Agreement; and (b) resolution to recommend that Masonite shareholders vote in favor of the Arrangement Resolution:

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The Board of Directors was also aware of and considered a number of risks and other factors concerning the Arrangement as generally negative or unfavorable, including the following (which risks and factors are not necessarily presented in order of relative importance):

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The foregoing discussion of reasons for the recommendation to adopt the Arrangement Agreement is not meant to be exhaustive but addresses the material information and factors considered by the Board of Directors in consideration of its recommendation. In view of the wide variety of factors considered by the Board of Directors in connection with its evaluation of the Arrangement and the complexity of these matters, the Board of Directors did not find it practicable to, and did not, quantify or otherwise assign relative weights to the specific factors considered in reaching its determination and recommendation. Rather, in considering the information and factors described above, individual members of the Board of Directors each applied his or her own personal business judgment to the process and may have given differing weights to differing factors. The Board of Directors based its unanimous recommendation on the totality of the information considered. The explanation of the factors and reasoning set forth above contain forward-looking statements that should be read in conjunction with the section of this proxy statement captioned “Forward-Looking Statements.”

Opinion of Goldman Sachs

Goldman Sachs rendered its opinion to the Board of Directors that, as of February 8, 2024 and based upon and subject to the factors and assumptions set forth therein, the Per Share Arrangement Consideration to be paid to the holders (other than Owens Corning and its affiliates) of Masonite common shares pursuant to the Arrangement Agreement was fair from a financial point of view to such holders.

The full text of the written opinion of Goldman Sachs, dated February 8, 2024, which sets forth assumptions made, procedures followed, matters considered and limitations on the review undertaken in connection with the opinion, is attached as Annex E. Goldman Sachs provided advisory services and its opinion for the information and assistance of the Board of Directors in connection with its consideration of the Arrangement. Goldman Sachs’ opinion is not a recommendation as to how any holder of Masonite common shares should vote with respect to the Arrangement, or any other matter.

In connection with rendering the opinion described above and performing its related financial analyses, Goldman Sachs reviewed, among other things:

Goldman Sachs also held discussions with members of the senior management of Masonite regarding their assessment of the past and current business operations, financial condition and future prospects of Masonite; reviewed the reported price and trading activity for Masonite common shares; compared certain financial and stock market information for Masonite with similar information for certain other companies the securities of which are publicly traded; reviewed the financial terms of certain recent business combinations in the building products industry and in other industries; and performed such other studies and analyses, and considered such other factors, as it deemed appropriate.

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For purposes of rendering this opinion, Goldman Sachs, with Masonite’s consent, relied upon and assumed the accuracy and completeness of all of the financial, legal, regulatory, tax, accounting and other information provided to, discussed with or reviewed by, it, without assuming any responsibility for independent verification thereof. In that regard, Goldman Sachs assumed with Masonite’s consent that the Management Projections were reasonably prepared on a basis reflecting the best then available estimates and judgments of the management of Masonite. Goldman Sachs did not make an independent evaluation or appraisal of the assets and liabilities (including any contingent, derivative or other off-balance-sheet assets and liabilities) of Masonite or any of its subsidiaries and it was not furnished with any such evaluation or appraisal. Goldman Sachs assumed that all governmental, regulatory or other consents and approvals necessary for the consummation of the Arrangement will be obtained without any adverse effect on the expected benefits of the Arrangement in any way meaningful to its analysis. Goldman Sachs also assumed that the Arrangement will be consummated on the terms set forth in the Arrangement Agreement, without the waiver or modification of any term or condition the effect of which would be in any way meaningful to its analysis.

Goldman Sachs’ opinion does not address the underlying business decision of Masonite to engage in the Arrangement or the relative merits of the Arrangement as compared to any strategic alternatives that may be available to Masonite; nor does it address any legal, regulatory, tax or accounting matters. Goldman Sachs’ opinion addresses only the fairness from a financial point of view to the holders (other than Owens Corning and its affiliates) of Masonite common shares, as of the date of the opinion, of the Per Share Arrangement Consideration to be paid to such holders pursuant to the Arrangement Agreement. Goldman Sachs’ opinion does not express any view on, and does not address, any other term or aspect of the Arrangement Agreement or the Arrangement or any term or aspect of any other agreement or instrument contemplated by the Arrangement Agreement or entered into or amended in connection with the Arrangement, including the fairness of the Arrangement to, or any consideration received in connection therewith by, the holders of any other class of securities, creditors, or other constituencies of Masonite; nor as to the fairness of the amount or nature of any compensation to be paid or payable to any of the officers, directors or employees of Masonite, or class of such persons, in connection with the Arrangement, whether relative to the Per Share Arrangement Consideration to be paid to the holders (other than Owens Corning and its affiliates) of Masonite common shares pursuant to the Arrangement Agreement or otherwise. Goldman Sachs’ opinion is necessarily based on economic, monetary market and other condition as in effect on, and the information made available to Goldman Sachs as of, the date of its opinion and Goldman Sachs assumes no responsibility for updating, revising or reaffirming its opinion based on circumstances, developments or events occurring after the date of its opinion. In addition, Goldman Sachs does not express any opinion as to the prices at which Masonite common shares will trade at any time or, as to the potential effects of volatility in the credit, financial and stock markets on Masonite, Owens Corning or the Arrangement, or as to the impact of the Arrangement on the solvency or viability of Masonite or Owens Corning or the ability of Masonite or Owens Corning to pay their respective obligations when they come due. Goldman Sachs’ opinion was approved by a fairness committee of Goldman Sachs.

The following is a summary of the material financial analyses delivered by Goldman Sachs to the Board of Directors in connection with rendering the opinion described above. The following summary, however, does not purport to be a complete description of the financial analyses performed by Goldman Sachs, nor does the order of analyses described represent relative importance or weight given to those analyses by Goldman Sachs. Some of the summaries of the financial analyses include information presented in tabular format. The tables must be read together with the full text of each summary and are alone not a complete description of Goldman Sachs’ financial analyses. Except as otherwise noted, the following quantitative information, to the extent that it is based on market data, is based on market data as it existed on or before February 8, 2024, the last trading day before the public announcement of the Arrangement, and is not necessarily indicative of current market conditions.

Historical Stock Trading Analysis. Goldman Sachs reviewed the historical trading prices and volumes for the Masonite common shares for the one-year period ended February 7, 2024. In addition, Goldman Sachs analyzed the consideration to be paid to holders of Masonite common shares pursuant to the Arrangement Agreement in relation to the (i) the closing price per Masonite common share on February 7, 2024, (ii) the

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volume weighted average price (the “VWAP”) of the Masonite common shares for the preceding 30-calendar day period ending February 7, 2024, (iii) the VWAP of the Masonite common shares for the preceding 60-calendar day period ending February 7, 2024, (iv) the VWAP of the Masonite common shares for the preceding 90-calendar day period ending February 7, 2024, (v) the 52-week high price per Masonite common share as of February 7, 2024, and (vi) the all-time high price per Masonite common share as of February 7, 2024.

This analysis indicated that the price per share to be paid to Masonite shareholders pursuant to the Arrangement Agreement represented:

Illustrative Discounted Cash Flow Analysis. Using the Management Projections, Goldman Sachs performed an illustrative discounted cash flow analysis on Masonite to derive a range of illustrative present values per Masonite common share. Using the mid-year convention for discounting cash flows and discount rates ranging from 9.0% to 11.0%, reflecting estimates of Masonite’s weighted average cost of capital, Goldman Sachs discounted to present value as of September 30, 2023 (i) estimates of unlevered free cash flow for Masonite for the fiscal years 2023 through 2028 as approved by Masonite’s management and (ii) a range of illustrative terminal values for Masonite, which were calculated by applying terminal year exit enterprise value (“EV”) to last twelve month (“LTM”) EBITDA (“EV/LTM EBITDA”) multiples ranging from 7.0x to 8.0x, to a terminal year estimate of EBITDA to be generated by Masonite, as reflected in the Management Projections (which analysis implied perpetuity growth rate of 2.8% at mid-point of the discounted cash flow range). The range of terminal year exit EV/LTM EBITDA multiples was estimated by Goldman Sachs utilizing its professional judgment and experience, taking into account historical trading multiples of Masonite and of certain publicly traded companies, as described below in the section captioned “—Selected Public Company Comparables Analysis.” Goldman Sachs derived such discount rates by application of the Capital Asset Pricing Model, which requires certain company-specific inputs, including Masonite’s target capital structure weightings, the cost of long-term debt, after-tax yield on permanent excess cash, if any, future applicable marginal cash tax rate and a beta for Masonite, as well as certain financial metrics for the United States financial markets generally.

Goldman Sachs derived ranges of illustrative enterprise values for Masonite by adding the ranges of present values it derived above. Goldman Sachs then subtracted from the range of illustrative enterprise values it derived for Masonite the amount of Masonite’s net debt as provided by and approved for Goldman Sachs’ use by the management of Masonite, to derive a range of illustrative equity values for Masonite. Goldman Sachs then divided the range of illustrative equity values it derived by the number of fully diluted outstanding Masonite common shares, as provided by and approved for Goldman Sachs’ use by the management of Masonite, using the treasury stock method, to derive a range of illustrative present values per share ranging from $122.00 to $153.00.

Illustrative Present Value of Future Share Price Analysis. Using the Management Projections, Goldman Sachs performed an illustrative analysis of the implied present value of an illustrative future value per Masonite

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common share. For this analysis, Goldman Sachs first calculated the implied enterprise value for Masonite for each of the fiscal years 2024 and 2025, by applying a range of multiples of illustrative EV to next twelve month (“NTM”) EBITDA (“EV/NTM EBITDA”) of 6.25x to 7.25x to estimates of Masonite’s NTM EBITDA for each of the fiscal years 2024 and 2025. This illustrative range of EV/NTM EBITDA multiple estimates was derived by Goldman Sachs utilizing its professional judgment and experience, taking into account current and historical EV/NTM EBITDA multiples for Masonite and current and historical EV/NTM EBITDA multiples for certain publicly traded companies, as described below in the section captioned “—Selected Public Company Comparables Analysis.”

Goldman Sachs then subtracted the amount of Masonite’s net debt for each of the fiscal years 2024 to 2025, each as provided by and approved for Goldman Sachs’ use by the management of Masonite, from the respective implied enterprise values in order to derive a range of illustrative equity values as of September 30, 2023 for Masonite for each of the fiscal years 2024 to 2025. Goldman Sachs then divided these implied equity values by the projected year-end number of fully diluted outstanding Masonite common shares for each of fiscal years 2024 to 2025, calculated using information provided by and approved for Goldman Sachs’ use by the management of Masonite, to derive a range of implied future values per Masonite common share (excluding dividends). Goldman Sachs then discounted these implied future equity values per Masonite common share to September 30, 2023, using an illustrative discount rate of 11.5%, reflecting an estimate of Masonite’s cost of equity. Goldman Sachs derived such discount rate by application of the Capital Asset Pricing Model, which requires certain company-specific inputs, including a beta for Masonite, as well as certain financial metrics for the United States financial markets generally. This analysis resulted in a range of implied present values of $101.00 to $150.00 per Share.

Selected Transactions Analysis. Goldman Sachs analyzed certain information relating to the following selected transactions in the building products industry since 2017. For each of the selected transactions, Goldman Sachs calculated and compared the implied enterprise value of the applicable target company based on the consideration paid in the transaction as a multiple of the target company’s LTM adjusted EBITDA based on information in public filings, press releases and investor relations documents. While none of the companies that participated in the selected transactions are directly comparable to Masonite, the companies that participated in the selected transactions are companies with operations that, for the purposes of analysis, may be considered similar to certain of Masonite’s results, market sizes and product profile.

The following table presents the results of this analysis:

Based on the results of the foregoing calculations and Goldman Sachs’ professional judgment and experience, Goldman Sachs applied a reference range of EV/LTM adjusted EBITDA multiples of 8.0x to 10.3x to Masonite’s LTM adjusted EBITDA as of September 30, 2023, as provided by and approved for Goldman Sachs’ use by the management of Masonite, to derive a range of implied enterprise values for Masonite.

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Goldman Sachs then subtracted the net debt of Masonite as of September 30, 2023, as provided by and approved for Goldman Sachs’ use by the management of Masonite, and divided the result by the number of fully diluted outstanding Masonite common shares as of September 30, 2023 as provided by and approved for Goldman Sachs’ use by the management of Masonite, to derive a reference range of implied values per Masonite common share of $119.00 to $164.00.

Premia Paid Analysis. Goldman Sachs reviewed and analyzed, using publicly available information, the acquisition premia for all-cash acquisition transactions announced from January 1, 2018 through February 7, 2024 involving a public company based in the United States as the target where the disclosed enterprise values for the transaction were between $1,000,000,000 and $5,000,000,000. This analysis excluded transactions with premia greater than 300% relative to the target’s last closing price prior to announcement and leveraged buyouts, and only included transactions with targets whose last undisturbed price was trading at 80% to 100% of its 52-week high price. For the entire period, using publicly available information, Goldman Sachs calculated the median, 25th percentile and 75th percentile premiums of the price paid in the all-cash U.S. public transactions relative to the target’s last closing stock price prior to announcement of the transaction. This analysis indicated a median premium of 24% across the period. This analysis also indicated a 25th percentile premium of 14% and 75th percentile premium of 46% across the period. Using this analysis, Goldman Sachs applied a reference range of illustrative premiums of 14% to 46% to the closing price per Masonite common share of $95.26 as of February 7, 2024 and calculated a range of implied equity values per Masonite common share of $109.00 to $139.00.

Selected Public Company Comparables Analysis. Goldman Sachs reviewed and compared certain financial information for Masonite to corresponding financial information, ratios and public market multiples for the following publicly traded corporations in the building products industry, which we refer to in this section of the proxy statement as the “Selected Companies”:

Although none of the Selected Companies is directly comparable to Masonite, the Selected Companies included were chosen because they are publicly traded companies in the building products industry with operations that, for purposes of analysis, may be considered similar to certain operations of Masonite.

Goldman Sachs also calculated and compared EV/LTM EBITDA and EV/NTM EBITDA multiples with respect to Masonite and the Selected Companies based on financial and trading data as of February 7, 2024, information Goldman Sachs obtained from public filings, Factset, and the Management Projections. With respect to Masonite and the Selected Companies, Goldman Sachs calculated:

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The results of these calculations are summarized as follows:

The preparation of a fairness opinion is a complex process and is not necessarily susceptible to partial analysis or summary description. Selecting portions of the analyses or of the summary set forth above, without considering the analyses as a whole, could create an incomplete view of the processes underlying Goldman Sachs’ opinion. In arriving at its fairness determination, Goldman Sachs considered the results of all of its analyses and did not attribute any particular weight to any factor or analysis considered by it. Rather, Goldman Sachs made its determination as to fairness on the basis of its experience and professional judgment after considering the results of all of its analyses. No company or transaction used in the above analyses as a comparison is directly comparable to Masonite or Owens Corning or the contemplated transaction.

Goldman Sachs prepared these analyses for purposes of Goldman Sachs providing its opinion to the Board of Directors as to the fairness from a financial point of view to the holders (other than Owens Corning and its affiliates) of Masonite common shares, as of the date of the opinion, of the Per Share Arrangement Consideration to be paid to such holders pursuant to the Arrangement Agreement. These analyses do not purport to be appraisals nor do they necessarily reflect the prices at which businesses or securities actually may be sold. Analyses based upon forecasts of future results are not necessarily indicative of actual future results, which may be significantly more or less favorable than suggested by these analyses. Because these analyses are inherently subject to uncertainty, being based upon numerous factors or events beyond the control of the parties or their respective advisors, none of Masonite, Owens Corning, Goldman Sachs or any other person assumes responsibility if future results are materially different from those forecast.

The Per Share Arrangement Consideration was determined through arm’s-length negotiations between Masonite and Owens Corning and was approved by the Board of Directors. Goldman Sachs did not recommend any specific amount of consideration to Masonite or the Board of Directors or that any specific amount of consideration constituted the only appropriate consideration for the Arrangement.

As described above, Goldman Sachs’ opinion to the Board of Directors was one of many factors taken into consideration by the Board of Directors in making its determination to approve the Arrangement Agreement. The foregoing summary does not purport to be a complete description of the analyses performed by Goldman Sachs in connection with the fairness opinion and is qualified in its entirety by reference to the written opinion of Goldman Sachs attached as Annex E.

Goldman Sachs and its affiliates are engaged in advisory, underwriting, lending and financing, principal investing, sales and trading, research, investment management and other financial and non-financial activities and services for various persons and entities. Goldman Sachs and its affiliates and employees, and funds or other entities they manage or in which they invest or have other economic interests or with which they co-invest, may at any time purchase, sell, hold or vote long or short positions and investments in securities, derivatives, loans, commodities, currencies, credit default swaps and other financial instruments of Masonite, Owens Corning, any of their respective affiliates and third parties, or any currency or commodity that may be involved in the transaction contemplated by the Arrangement Agreement. Goldman Sachs acted as financial advisor to Masonite in connection with, and participated in certain of the negotiations leading to, the Arrangement. During the

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two-year period ended February 8, 2024, Goldman Sachs Investment Banking has not been engaged by Masonite or its affiliates to provide financial advisory or underwriting services for which Goldman Sachs has recognized compensation. During the two-year period ended February 8, 2024, Goldman Sachs Investment Banking has not been engaged by Owens Corning or its affiliates to provide financial advisory or underwriting services for which Goldman Sachs has recognized compensation. Goldman Sachs may also in the future provide financial advisory and/or underwriting services to Masonite, Owens Corning and their respective affiliates for which Goldman Sachs Investment Banking may receive compensation.

The Board of Directors selected Goldman Sachs as its financial advisor because it is an internationally recognized investment banking firm that has substantial experience in transactions similar to the Arrangement. Pursuant to a letter agreement dated June 28, 2023, Masonite engaged Goldman Sachs to act as its financial advisor in connection with the Arrangement. The engagement letter between Masonite and Goldman Sachs provides for a transaction fee that is estimated, based on the information available as of the date of announcement, at approximately $35 million, all of which is contingent upon consummation of the Arrangement. In addition, Masonite has agreed to reimburse Goldman Sachs for certain of its expenses, including attorneys’ fees and disbursements, and to indemnify Goldman Sachs and related persons against various liabilities, including certain liabilities under the federal securities laws.

Opinion of Jefferies LLC

Masonite has retained Jefferies as a financial advisor to Masonite in connection with the Arrangement. In connection with this engagement, the Board of Directors requested that Jefferies evaluate the fairness, from a financial point of view, of the Per Share Arrangement Consideration to be received in the Arrangement by holders of Masonite common shares (other than, as applicable, Owens Corning, Purchaser and their respective affiliates) pursuant to the Arrangement Agreement. At a meeting of the Board of Directors held on February 8, 2024 to evaluate the Arrangement, Jefferies rendered an oral opinion, confirmed by delivery of a written opinion dated February 8, 2024, to the Board of Directors to the effect that, as of that date and based on and subject to various assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken as described in its opinion, the Per Share Arrangement Consideration to be received in the Arrangement by holders of Masonite common shares (other than, as applicable, Owens Corning, Purchaser and their respective affiliates) pursuant to the Arrangement Agreement was fair, from a financial point of view, to such holders.

The full text of Jefferies’ opinion, which describes various assumptions made, procedures followed, matters considered and limitations and qualifications on the review undertaken by Jefferies, is attached as Annex F to this proxy statement and is incorporated herein by reference. Jefferies’ opinion was provided for the use and benefit of the Board of Directors (in its capacity as such) in its evaluation of the Per Share Arrangement Consideration from a financial point of view and did not address any other aspect of the Arrangement or any other matter. Jefferies’ opinion did not address the relative merits of the Arrangement or other transactions contemplated by the Arrangement Agreement as compared to any alternative transaction or opportunity that might be available to Masonite, nor did it address the underlying business decision by Masonite to engage in the Arrangement. Jefferies’ opinion did not constitute a recommendation as to how the Board of Directors, and does not constitute a recommendation as to how any securityholder, should vote or act with respect to the Arrangement or any other matter. The following summary is qualified in its entirety by reference to the full text of Jefferies’ opinion.

In arriving at its opinion, Jefferies, among other things:

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In its review and analysis and in rendering its opinion, Jefferies assumed and relied upon, but did not assume any responsibility to independently investigate or verify, the accuracy and completeness of all financial and other information that was supplied or otherwise made available by Masonite or that was publicly available to Jefferies (including, without limitation, the information described above) or otherwise reviewed by Jefferies. Jefferies relied on assurances of the management and other representatives of Masonite that they were not aware of any facts or circumstances that would make such information incomplete, inaccurate or misleading. Jefferies did not make nor did it obtain an independent evaluation or appraisal of any of the assets or liabilities (contingent, accrued, derivative, off-balance sheet or otherwise), nor did Jefferies conduct a physical inspection of any of the properties or facilities, of Masonite or any other entity and Jefferies was not furnished with, and assumed no responsibility to obtain or conduct, any such evaluations, appraisals or physical inspections. Jefferies also did not evaluate the solvency or fair value of Masonite or any other entity under any state, provincial or federal laws relating to bankruptcy, insolvency or similar matters. In addition, Jefferies’ analyses and opinion did not consider any actual or potential arbitration, litigation, claims or possible unasserted claims, audits, investigations or other proceedings involving or affecting Masonite or any other entity.

With respect to the financial forecasts and estimates provided to and reviewed by Jefferies, Jefferies noted that projecting future results of any company is inherently subject to uncertainty. However, Jefferies was advised, and assumed, that the financial forecasts and estimates relating to Masonite that Jefferies was directed to utilize for purposes of its analyses and opinion were reasonably prepared on bases reflecting the best currently available estimates and good faith judgments of the management of Masonite as to, and were an appropriate basis upon which to evaluate, the future financial performance of Masonite and the other matters covered thereby. Jefferies expressed no opinion as to any financial forecasts or estimates or the assumptions on which they were based.

Jefferies relied upon the assessments of the management of Masonite as to, among other things, (a) the potential impact on Masonite of market, competitive, seasonal, macroeconomic, geopolitical and other conditions, trends and developments in and prospects for, and governmental, regulatory and legislative matters relating to or otherwise affecting, the building products industry, including the sectors and geographic regions in which Masonite operates, and the availability and pricing of commodities, raw materials and finished goods, which are subject to significant volatility and which, if different than as assumed, could have a material impact on Jefferies’ analyses or opinion, (b) Masonite’s anticipated divestiture and completed acquisitions, including financial and other aspects involved and the ability to integrate acquired businesses and realize the potential benefits thereof, (c) the existing and future products and intellectual property of Masonite, and (d) Masonite’s existing and future agreements and other arrangements involving, and ability to attract, retain and/or replace, key employees, customers, suppliers, transportation providers and other commercial relationships. Jefferies assumed that there would not be any developments with respect to any such matters that would have an adverse effect on Masonite or the Arrangement or that otherwise would be meaningful in any respect to Jefferies’ analyses or opinion.

Jefferies’ opinion was based on economic, monetary, regulatory, market and other conditions existing, and which could be evaluated, as of the date of Jefferies’ opinion. Jefferies expressly disclaimed any undertaking or obligation to advise any person of any change in any fact or matter affecting its opinion of which Jefferies

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becomes aware after the date of its opinion. As the Board of Directors was aware, the credit, financial and stock markets and the industry and sectors in which Masonite operates have experienced and may continue to experience volatility and disruptions and Jefferies expressed no view or opinion as to any potential effects of such volatility or disruptions on Masonite or the Arrangement.

Jefferies made no independent investigation of, and Jefferies expressed no view or opinion as to, any legal, regulatory, accounting or tax matters affecting or relating to Masonite or the Arrangement and Jefferies assumed the correctness in all respects meaningful to its analyses and opinion of all legal, regulatory, accounting and tax advice given to Masonite and/or the Board of Directors, including, without limitation, with respect to changes in, or the impact of, accounting standards or tax and other laws, regulations and governmental and legislative policies affecting Masonite or the Arrangement and legal, regulatory, accounting and tax consequences to Masonite or its securityholders of the terms of, and transactions contemplated by, the Arrangement Agreement. Jefferies also assumed that the Arrangement would be consummated in accordance with its terms without waiver, modification or amendment of any material term, condition or agreement and in compliance with all applicable laws, documents and other requirements and that, in the course of obtaining the necessary governmental, regulatory or third-party approvals, consents, waivers and releases for the Arrangement or otherwise, including with respect to any divestitures or other requirements, no delay, limitation, restriction or condition would be imposed or occur that would have an adverse effect on Masonite or the Arrangement or that otherwise would be meaningful in any respect to Jefferies’ analyses or opinion. Jefferies assumed that the final Arrangement Agreement, when signed by the parties thereto, would not differ from the draft reviewed by Jefferies in any respect meaningful to Jefferies’ analyses or opinion.

As the Board of Directors was aware, in connection with Jefferies’ engagement, Jefferies was not requested to, and Jefferies did not, solicit indications of interest or proposals from third parties regarding the possible acquisition of all or a part of Masonite or any alternative transaction. Jefferies’ opinion did not address the relative merits of the Arrangement or other transactions contemplated by the Arrangement Agreement as compared to any alternative transaction or opportunity that might be available to Masonite, nor did it address the underlying business decision by Masonite to engage in the Arrangement or the terms of the Arrangement Agreement, including the form or structure of Arrangement or any term, aspect or implication of any agreements, arrangements or understandings entered into in connection with, or contemplated by or resulting from, the Arrangement or otherwise. Jefferies’ opinion was limited to the fairness, from a financial point of view and as of the date of such opinion, of the Per Share Arrangement Consideration to be received by holders of Masonite common shares (to the extent expressly specified in such opinion), without regard to individual circumstances of specific holders (whether by virtue of control, voting or consent, liquidity, contractual arrangements or otherwise) which may distinguish such holders or the securities of Masonite held by such holders, and Jefferies’ opinion did not in any way address proportionate allocation or relative fairness among such holders, holders of any other securities of Masonite or otherwise. Jefferies was not asked to, and its opinion did not, address the fairness, financial or otherwise, of any consideration to the holders of any class of securities, creditors or other constituencies of Masonite or any other party. Furthermore, Jefferies expressed no view or opinion as to the fairness, financial or otherwise, of the amount or nature of any compensation or other consideration payable to or to be received by any officers, directors or employees, or any class of such persons, in connection with the Arrangement relative to the Per Share Arrangement Consideration or otherwise. Jefferies also expressed no view or opinion as to the prices at which Masonite common shares or any other securities of Masonite may trade or otherwise be transferable at any time, including following announcement or consummation of the Arrangement. The issuance of Jefferies’ opinion was authorized by Jefferies’ fairness committee.

In connection with rendering its opinion to the Board of Directors, Jefferies performed a variety of financial and comparative analyses, including those described below. The following summary is not a complete description of all analyses performed and factors considered by Jefferies in connection with its opinion. The preparation of a financial opinion is a complex process involving subjective judgments and is not necessarily susceptible to partial analysis or summary description. With respect to the selected public companies and selected precedent transactions analyses summarized below, no company or transaction used as a comparison was

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identical or directly comparable to Masonite or the Arrangement. These analyses necessarily involved complex considerations and judgments concerning financial and operating characteristics and other factors that could affect the public trading, acquisition or other values of the companies or transactions concerned.

Jefferies believes that its analyses and the summary below must be considered as a whole and in context and that selecting portions of its analyses and factors or focusing on information presented in tabular format, without considering all analyses and factors or the narrative description of the analyses, could create a misleading or incomplete view of the processes underlying Jefferies’ analyses and opinion. Jefferies did not draw, in isolation, conclusions from or with regard to any one factor or method of analysis for purposes of its opinion, but rather arrived at its ultimate opinion based on the results of all analyses undertaken by it and assessed as a whole.

The estimates of the future performance of Masonite in or underlying Jefferies’ analyses are not necessarily indicative of future results or values, which may be significantly more or less favorable than those estimates. In performing its analyses, Jefferies considered industry performance, general business and economic conditions and other matters, many of which are beyond the control of Masonite. Estimates of the financial value of companies or businesses do not purport to be appraisals or necessarily reflect the prices at which companies, businesses or securities actually may be sold or acquired. Accordingly, the estimates used in, and the implied reference ranges resulting from, any particular analysis described below are inherently subject to substantial uncertainty and should not be taken as Jefferies’ view of the actual value of Masonite or its businesses or securities.

The Per Share Arrangement Consideration was determined through negotiations between Masonite and Owens Corning, and the decision by Masonite to enter into the Arrangement Agreement was solely that of the Board of Directors. Jefferies’ opinion and financial analyses were only one of many factors considered by the Board of Directors in its evaluation of the Per Share Arrangement Consideration and should not be viewed as determinative of the views of the Board of Directors or Masonite’s management with respect to the Arrangement or the Per Share Arrangement Consideration.

Financial Analyses

The summary of the financial analyses described in this section entitled “—Financial Analyses” is a summary of the material financial analyses reviewed with the Board of Directors and performed by Jefferies in connection with its opinion. The financial analyses summarized below include information presented in tabular format. In order to fully understand Jefferies’ financial analyses, the tables must be read together with the text of each summary. The tables alone do not constitute a complete description of the financial analyses. Considering the data below without considering the full narrative description of the financial analyses, including the methodologies and assumptions underlying the analyses, could create a misleading or incomplete view of Jefferies’ financial analyses. The order in which the financial analyses summarized below appear does not necessarily reflect the relative importance or weight given to such analyses. For purposes of the analyses described below, Masonite was evaluated pro forma for an anticipated divestiture and certain completed acquisitions and approximate implied per share equity value reference ranges derived from the financial analyses and certain additional information described below were rounded to the nearest $1.00.

Selected Public Companies Analysis. Jefferies reviewed publicly available financial, stock market and operating information of Masonite and the following five selected publicly traded companies with operations in the building products industry that Jefferies considered generally relevant for purposes of analysis (collectively, the “selected companies”):

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Jefferies reviewed enterprise values of the selected companies, calculated as fully diluted equity values based on closing stock prices on February 7, 2024 plus total debt, preferred equity and non-controlling interests (as applicable) and less cash and cash equivalents, as a multiple of calendar year 2024 estimated earnings before interest, taxes, depreciation and amortization (“EBITDA”). Financial data of the selected companies were based on publicly available research analysts’ estimates, public filings and other publicly available information. Financial data of Masonite was based on publicly available research analysts’ estimates, public filings and financial forecasts and estimates of the management of Masonite.

The overall low to high calendar year 2024 estimated EBITDA multiples observed for the selected companies was 6.5x to 12.3x (with a mean of 8.0x and a median of 7.0x). Jefferies noted that the calendar year 2024 estimated EBITDA multiple observed for Masonite was 6.9x based both on publicly available research analysts’ estimates (adjusted for an anticipated divestiture by Masonite) and financial forecasts and estimates of the management of Masonite. Jefferies then applied a selected range of calendar year 2024 estimated EBITDA multiples derived from the selected companies of 6.5x to 7.5x to corresponding data of Masonite based on financial forecasts and estimates of the management of Masonite. This analysis indicated the following approximate implied per share equity value reference range for Masonite, as compared to the Per Share Arrangement Consideration:

Selected Precedent Transactions Analysis. Jefferies reviewed, among other things, financial information for the following 11 selected transactions involving target companies with operations in the building products industry that Jefferies considered generally relevant for purposes of analysis (collectively, the “selected transactions”):

Jefferies reviewed transaction values of the selected transactions, calculated as the enterprise values implied for the target companies based on the consideration paid in the selected transactions, as a multiple of such target companies’ latest 12 months EBITDA as reported prior to or as of the applicable announcement date of such transactions. Financial data of the selected transactions were based on publicly available research analysts’ estimates, public filings and other publicly available information. Financial data of Masonite was based on public filings and financial forecasts and estimates of the management of Masonite.

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The overall low to high latest 12 months EBITDA multiples observed for the selected transactions was 6.6x to 11.0x (with a mean and median of 9.1x). Jefferies applied a selected range of latest 12 months EBITDA multiples derived from the selected transactions of 8.0x to 10.0x to the calendar year 2023 estimated EBITDA of Masonite. This analysis indicated the following approximate implied per share equity value reference range for Masonite, as compared to the Per Share Arrangement Consideration:

Discounted Cash Flow Analysis. Jefferies performed a discounted cash flow analysis of Masonite by calculating the estimated present value of the standalone unlevered, after-tax free cash flows that Masonite was forecasted to generate during Masonite’s fiscal years 2024 through 2028 based on financial forecasts and estimates of the management of Masonite. For purposes of this analysis, stock-based compensation was treated as a cash expense. The implied terminal value of Masonite was derived by applying a selected range of perpetuity growth rates of 1.5% to 2.5% to Masonite’s unlevered after-tax free cash flow for fiscal year 2028. The present values (as of December 31, 2023) of the cash flows and terminal values were then calculated using a selected range of discount rates of 11.5% to 12.5%. This analysis indicated the following approximate implied per share equity value reference range for Masonite, as compared to the Per Share Arrangement Consideration:

Certain Additional Information

Jefferies observed certain additional information that was not considered part of Jefferies’ financial analysis with respect to its opinion but was noted for informational purposes, including the implied premiums paid or proposed to be paid in selected mergers and acquisition transactions announced from January 1, 2018 through February 7, 2024 with transaction values of $500 million to $5 billion involving target companies publicly traded in the U.S. or Canada; applying a selected range of implied premiums of approximately 14.3% to 43.9% (reflecting the overall 25th and 75th percentile implied premiums derived from such transactions based on the closing stock prices of the target companies involved in such transactions 30 calendar days prior to public announcement of such transactions) to the closing price of Masonite common shares on February 7, 2024 of $95.26 per share indicated an approximate implied equity value reference range for Masonite of approximately $109.00 per share to $137.00 per share.

Miscellaneous

Masonite has agreed to pay Jefferies for its financial advisory services in connection with the Arrangement a fee of $5 million payable upon delivery of Jefferies’ opinion (which fee is not contingent upon consummation of the Arrangement). In addition, Masonite agreed to reimburse Jefferies for expenses, including fees and expenses of counsel, incurred in connection with Jefferies’ engagement and to indemnify Jefferies and related parties against liabilities, including liabilities under federal securities laws, arising out of or in connection with the services rendered and to be rendered by Jefferies under its engagement.

As the Board of Directors was aware, Jefferies and its affiliates in the past have provided, and in the future may provide, certain financial advisory or financing services to Masonite unrelated to the Arrangement, for which services Jefferies and its affiliates have received and may receive compensation, including, during the approximate two-year period prior to the date of Jefferies’ opinion, having acted as financial advisor to Masonite in connection with a potential acquisition transaction for which financial advisory services Jefferies has received a fee of approximately $17.5 million. Although Jefferies and its affiliates had not provided financial advisory or financing services to Owens Corning during the two-year period prior to the date of Jefferies’ opinion for which

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Jefferies and its affiliates received compensation, Jefferies and its affiliates in the future may provide such services to Owens Corning and/or its affiliates for which services Jefferies and/or its affiliates would expect to receive compensation. In the ordinary course of business, Jefferies and its affiliates may trade or hold securities or financial instruments (including loans and other obligations) of Masonite, Owens Corning and/or their respective affiliates for Jefferies’ own account and for the accounts of its customers and, accordingly, may at any time hold long or short positions or otherwise effect transactions in those securities or financial instruments.

Jefferies was selected as a financial advisor to Masonite in connection with the Arrangement because, among other things, Jefferies is an internationally recognized investment banking firm with substantial experience in merger and acquisition transactions and based on its familiarity with Masonite and its business. Jefferies is regularly engaged in the valuation of businesses and their securities in connection with mergers and acquisitions, leveraged buyouts, negotiated underwritings, competitive bids, secondary distributions of listed and unlisted securities and private placements.

Management Projections

Masonite does not, as a matter of course, publicly disclose long-term consolidated forecasts as to future performance, earnings or other results given, among other reasons, the uncertainty, unpredictability and subjectivity of the underlying assumptions and estimates. However, in connection with the Arrangement, Masonite’s management, at the request of the Board of Directors, provided the Board of Directors, Goldman Sachs, Jefferies and Owens Corning and its advisors with certain non-public, unaudited prospective financial information for the fiscal year ending December 31, 2024 through the fiscal year ending December 31, 2028 (collectively, the “Management Projections”) reflecting Masonite’s management’s best then-available estimates and judgments of the future financial performance of Masonite for such periods. The Management Projections were prepared on a standalone basis and do not take into account any of the transactions contemplated by the Arrangement Agreement, including any costs incurred in connection with the Arrangement, or any changes to Masonite’s operations or strategy that may be implemented after the completion of the Arrangement. As a result, actual results likely will differ, and may differ materially, from those contained in the Management Projections. You should note that the Management Projections constitute forward-looking statements.

Masonite’s management provided the Management Projections to the Board of Directors in connection with its evaluation of the Arrangement and to each of Goldman Sachs and Jefferies for their use and reliance as the basis for their respective financial analyses and opinions, as described in more detail in the sections of this proxy statement captioned “—Opinion of Goldman Sachs LLC” and “—Opinion of Jefferies LLC.” A summary of the Management Projections is included in this proxy statement solely to give Masonite shareholders access to certain non-public information that was provided to the Board of Directors, Goldman Sachs, Jefferies and Owens Corning and its advisors and is not included in this proxy statement to influence any Masonite shareholder to vote for the Arrangement Resolution, to vote against the Arrangement Resolution, or for any other purpose. The inclusion of this information should not be regarded as an indication that any of Masonite or its affiliates, officers, directors, advisors or other representatives or any other recipient of this information considered, or now considers, it to be necessarily predictive of actual future performance or events, or that it should be construed as financial guidance, and such summary projections set forth below should not be relied on as such.

While presented with numerical specificity, the Management Projections reflect numerous estimates and assumptions that are inherently uncertain and may be beyond the control of Masonite, including, among others, Masonite’s assumptions about supply chain constraints, manufacturing capacity, commodity prices, production and sales volume levels, operating results, competitive conditions, availability of capital resources, levels of capital expenditures, other contractual obligations, inflation and the supply of and demand for its products, as well as the other matters described in the section of this proxy statement captioned “Forward-Looking Statements.” The Management Projections reflect both assumptions as to certain business decisions that are subject to change and, in many respects, subjective judgment, and thus are susceptible to multiple interpretations and periodic revisions based on actual experience and business developments. Masonite can give no assurance

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that the Management Projections and the underlying estimates and assumptions will be realized. In addition, since the Management Projections cover multiple years, such information by its nature becomes subject to greater uncertainty with each successive year. This information constitutes “forward-looking statements” and actual results may differ materially and adversely from those projected. See the section of this proxy statement captioned “Forward-Looking Statements.”

The Management Projections were not prepared with a view toward public disclosure, nor were they prepared with a view toward compliance with U.S. generally accepted accounting principles (“GAAP”), published guidelines of the SEC or the guidelines established by the Public Company Accounting Oversight Board for preparation and presentation of prospective financial information. These non-GAAP financial measures should not be viewed as a substitute for GAAP financial measures and may be different from similarly titled non-GAAP financial measures used by other companies. Furthermore, there are limitations inherent in non-GAAP financial measures because they exclude charges and credits that are required to be included in a GAAP presentation. Accordingly, these non-GAAP financial measures should be considered together with, and not as an alternative to, financial measures prepared in accordance with GAAP. Financial measures included in forecasts provided to a financial advisor and a board of directors in connection with a business combination transaction, such as the Management Projections, are excluded from the definition of “non-GAAP financial measures” under applicable SEC rules and regulations. As a result, the Management Projections are not subject to SEC rules regarding disclosures of non-GAAP financial measures, which would otherwise require a reconciliation of a non-GAAP financial measure to a GAAP financial measure. Neither Masonite’s independent registered public accounting firm, nor any other independent accountants, have compiled, examined or performed any procedures with respect to the Management Projections, nor have they expressed any opinion or any other form of assurance on such information or their achievability. The report of the independent registered public accounting firm to Masonite contained in its Annual Report on Form 10-K for the year ended December 31, 2023 relates to historical financial information of Masonite, and such report does not extend to the projections included below and should not be read to do so.

Furthermore, the Management Projections do not take into account any circumstances or events occurring after the date on which they were prepared. Masonite can give no assurance that, had the Management Projections been prepared as of the date of this proxy statement, similar estimates and assumptions would be used. Except as required by applicable law, Masonite does not intend to, and disclaims any obligation to, make publicly available any update or other revision to the Management Projections to reflect circumstances existing since their preparation or to reflect the occurrence of unanticipated events, even in the event that any or all of the underlying assumptions are shown to be inappropriate or to reflect changes in general economic or industry conditions. The Management Projections do not take into account all the possible financial and other effects of the Arrangement on Masonite, the effect on Masonite of any business or strategic decision or action that has been or will be taken as a result of the Arrangement Agreement having been executed, or the effect of any business or strategic decisions or actions that would likely have been taken if the Arrangement Agreement had not been executed, but which were instead altered, accelerated, postponed or not taken in anticipation of the Arrangement. Further, the Management Projections do not take into account the effect on Masonite of any possible failure of consummation of the Arrangement. None of Masonite or its affiliates, officers, directors, advisors or other representatives has made, makes or is authorized in the future to make any representation to any Masonite shareholder or any other person regarding Masonite’s ultimate performance compared to the information contained in the Management Projections or to the effect that the forecasted results will be achieved. The inclusion of the Management Projections herein should not be deemed an admission or representation by Masonite or its affiliates, officers, directors, advisors or other representatives or any other person that the Management Projections are viewed as material information of Masonite, particularly in light of the inherent risks and uncertainties associated with such forecasts.

In light of the foregoing, as well as the uncertainties inherent in any forecasted information, Masonite shareholders are cautioned not to place undue reliance on such information, and Masonite urges all of its shareholders to review its most recent SEC filings for a description of Masonite’s reported financial results.

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The Management Projections are based on various assumptions, including, but not limited to, the following principal assumptions:

The following table summarizes the Management Projections for the fiscal years 2024 through 2028 ($ in millions, unless otherwise stated):

Management Projections

MASONITE DOES NOT INTEND TO UPDATE OR OTHERWISE REVISE THE ABOVE MANAGEMENT PROJECTIONS TO REFLECT CIRCUMSTANCES EXISTING AFTER THE DATE WHEN MADE OR TO REFLECT THE OCCURRENCE OF FUTURE EVENTS, EVEN IN THE EVENT THAT ANY OR ALL OF THE ASSUMPTIONS UNDERLYING SUCH MANAGEMENT PROJECTIONS ARE NO LONGER APPROPRIATE, EXCEPT AS MAY BE REQUIRED BY APPLICABLE LAW.

Interests of Masonite’s Executive Officers and Directors in the Arrangement

In considering the recommendation of the Board of Directors that Masonite shareholders adopt the Arrangement Agreement, Masonite shareholders should be aware that the executive officers and directors of Masonite have certain interests in the Arrangement that may be different from, or in addition to, the interests of Masonite shareholders generally. The Board of Directors was aware of these interests and considered them, among other matters, in approving the Arrangement Resolution and the transactions contemplated hereby, including the Arrangement, and in making their recommendation that Masonite shareholders approve the Arrangement Resolution.

For purposes of this disclosure, Masonite’s named executive officers are:

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Masonite’s executive officers consist of its named executive officers, as well as Alexander A. Legall (Senior Vice President, Business Leader, Architectural), James C. Pelletier (Senior Vice President, General Counsel and Corporate Secretary) and Katie Shellabarger (Vice President, Chief Accounting Officer).

Certain Assumptions

Except as otherwise specifically noted, for purposes of quantifying the potential payments and benefits described in this section, the following assumptions were used:

The amounts indicated below are estimates based on multiple assumptions that may or may not actually occur or be accurate on the relevant date, including the assumptions described above, and do not reflect certain compensation actions that may occur before completion of the Arrangement.

Treatment of Masonite Equity Awards

Each Masonite RSU Award and each Masonite PRSU Award that is held by an employee and does not vest on or prior to the Effective Time by its terms will be exchanged at the Effective Time for an Owens Corning RSU Award subject to substantially the same terms and conditions as applied to the corresponding Masonite RSU Award or Masonite PRSU Award immediately prior to the Effective Time, with the number of shares of Owens Corning common stock underlying such Owens Corning RSU Award equal to the product, rounded to the nearest whole share, obtained by multiplying (a) the number of Masonite common shares underlying the Masonite RSU Award or Masonite PRSU Award immediately prior to the Effective Time by (b) the Equity Award Exchange Ratio. All Masonite RSU Awards and Masonite PRSU Awards that vest on or prior to the Effective Time or are held by an individual who is not an employee will be canceled at the Effective Time in exchange for the Per Share Arrangement Consideration in respect of each Masonite common share subject to such Masonite RSU Award or Masonite PRSU Award. All Masonite RSU Awards held by non-employee directors will be canceled at the Effective Time in exchange for the Per Share Arrangement Consideration in respect of each Masonite common share subject to such Masonite RSU Award.

The number of Masonite common shares subject to Masonite PRSU Awards will be determined (a) with respect to performance periods that are complete as of the Effective Time, based on actual performance, and (b) with respect to performance periods that are incomplete as of the Effective Time, with performance goals deemed achieved at 122% of the target level (or, in the case of Masonite PRSU Awards that do not have a target level, such performance goals will be deemed fully satisfied).

The equity award agreements governing the Masonite RSU Awards provide that the vesting of awards assumed or substituted by an acquirer in a change in control would accelerate in full upon the holder’s qualifying

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termination within 30 days prior to or two years following a change in control (or the holder’s termination without cause prior to a change in control at the request of a third party or otherwise in anticipation of a change in control).

Each Masonite SAR Award will be canceled at the Effective Time in exchange for a cash payment in respect of each share of Masonite common stock subject to such Masonite SAR Award equal to the excess (if any) of the Per Share Arrangement Consideration over the applicable exercise price.

See the sections of this proxy statement captioned “—Quantification of Potential Payments and Benefits to Masonite’s Named Executive Officers in Connection with the Arrangement” for the estimated value of each named executive officer’s unvested Masonite’s equity awards. Based on the assumptions described above under the section of this proxy statement captioned “—Certain Assumptions,” the estimated aggregate value of the unvested Masonite equity awards held by (a) Masonite’s other executive officers that would vest upon a qualifying termination is $5,386,198 and (b) Masonite’s nonemployee directors that would vest at the Effective Time is $1,263,766.

Treatment of Annual Bonus

Under the terms of the Arrangement Agreement, if the Effective Time occurs prior to the date that finalized results are available in respect of fiscal year 2024, Owens Corning will pay annual incentives with respect to fiscal year 2024 no later than the time Masonite has historically paid annual incentives based upon the greater of (a) 50% of target performance and (b) actual performance, as determined by Owens Corning in good faith, except that in the case of an employee who experiences a qualifying termination on or before December 31, 2024, performance for fiscal year 2024 will be deemed achieved at 100% of target and such bonus will be prorated based on the number of days of such employee’s employment during fiscal year 2024 and paid promptly following the execution of a release of claims.

See the section of this proxy statement captioned “—Quantification of Potential Payments and Benefits to Masonite’s Named Executive Officers in Connection with the Arrangement” for the estimated amount of the prorated bonus payment that each of Masonite’s named executive officers would receive under the terms of the Arrangement Agreement. Based on the assumptions described above under the section of this proxy statement captioned “—Certain Assumptions,” the estimated aggregate value of the prorated bonus payment to Masonite’s other executive officers is $117,757.

Employment Agreements

Masonite is party to an employment agreement with each of its executive officers (other than Ms. Shellabarger). Under the employment agreements (taking into account certain modifications that Masonite is permitted to adopt under the Arrangement Agreement), upon a qualifying termination, including due to the employer’s non-renewal of the employment agreement, within two years following a change in control (or a termination without cause prior to a change in control at the request of a third party or otherwise in anticipation of a change in control), an executive officer would be entitled to:

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The foregoing termination benefits are generally subject to the executive officer’s execution of a release of claims and compliance with the restrictive covenants set forth in the employment agreement, including confidentiality (both during and after employment for a perpetual period), non-solicitation of customers and employees and non-competition for a period of 24 months after employment (in the case of Mr. Pelletier, his employment agreement does not contain non-competition or non-solicitation of customers covenants). If the compensation and benefits payable to an executive officer would be subject to an excise tax under Section 4999 of the Internal Revenue Code, such amounts shall either be paid in full or reduced to the level that would avoid application of the excise tax, whichever would place the executive officer in a better after-tax position. If it is determined that the Effective Time is not reasonably expected to occur in 2024, Masonite may accelerate the income otherwise payable to such individual in the ordinary course of business not later than March 31, 2025 into December 2024.

As noted above, Ms. Shellabarger is not party to an employment agreement with Masonite. In the event of her termination of employment without cause under Masonite’s existing severance arrangements, she would be eligible for severance compensation equal to 26 weeks of base salary.

See the section of this proxy statement captioned “—Quantification of Potential Payments and Benefits to Masonite’s Named Executive Officers in Connection with the Arrangement” for the estimated amounts that each of Masonite’s named executive officers would receive under his employment agreement. Based on the assumptions described above under the section of this proxy statement captioned “—Certain Assumptions,” the estimated aggregate value of the termination benefits to Masonite’s other executive officers under their employment agreements or, in the case of Ms. Shellabarger, under Masonite’s existing severance arrangements (other than the prorated bonus which is described and quantified above) is $3,439,471.

Potential Employment Arrangements with Owens Corning

Any of Masonite’s executive officers who become officers or employees or who otherwise are retained to provide services to Owens Corning or its affiliates may, prior to, on, or following the Effective Time, enter into new compensation arrangements with Owens Corning or its affiliates. As of the date of this proxy statement, no new individualized compensation arrangements between Masonite’s executive officers and Owens Corning or its affiliates have been established.

Indemnification and Insurance

Pursuant to the terms of the Arrangement Agreement, Masonite’s directors and executive officers will be entitled to certain ongoing indemnification and coverage for a period of six years following the effective time under directors’ and officers’ liability insurance policies from Masonite. This indemnification and insurance coverage is further described in the section of this proxy statement captioned “The Arrangement Agreement—Directors and Officers Indemnification and Insurance.”

Quantification of Potential Payments and Benefits to Masonite’s Named Executive Officers in Connection with the Arrangement

The information set forth in the table below is intended to comply with Item 402(t) of the SEC’s Regulation S-K, which requires disclosure of information about certain compensation for each named executive

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officer of Masonite that is based on, or otherwise relates to, the Arrangement. For additional details regarding the terms of the payments and benefits described below, see the discussion under the section of this proxy statement captioned “The Arrangement—Interests of Masonite’s Executive Officers and Directors in the Arrangement.”

The amounts shown in the table below are estimates based on multiple assumptions that may or may not actually occur or be accurate on the relevant date, including the assumptions described below and in the footnotes to the table, and do not reflect certain compensation actions that may occur before completion of the Arrangement. Such amounts are based on the assumptions described above under the section of this proxy statement captioned “—Certain Assumptions.”

For purposes of this disclosure, “single trigger” refers to payments and benefits that arise solely as a result of the completion of the Arrangement and “double trigger” refers to payments and benefits that require the completion of the Arrangement and a qualifying termination.

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For additional information, see the section of this proxy statement captioned “—Employment Agreements.” The estimated value of such benefits is shown in the following table:

Financing of the Arrangement

Owens Corning intends to fund the aggregate Per Share Arrangement Consideration with a combination of cash on hand and debt financing. On March 1, 2024, Owens Corning entered into the Credit Agreement with the Lenders and MSSF, as administrative agent, pursuant to which the Lenders committed to provide, subject to the satisfaction of customary closing conditions, the Term Facility.

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Owens Corning and Purchaser have represented to Masonite that, assuming the Term Facility is funded at or immediately prior to the Effective Time in accordance with the Credit Agreement and the Arrangement is completed in accordance with the terms of the Arrangement Agreement following satisfaction of the conditions precedent thereto, the aggregate proceeds of the Term Facility, together with any cash on hand, available lines of credit and other sources of immediately available funds, will be in an amount sufficient to enable Owens Corning to make the cash portion of the payment of the aggregate consideration payable by Purchaser pursuant to the Plan of Arrangement and any other amounts to be paid by Owens Corning or Purchaser under the Arrangement Agreement or under the Credit Agreement. Owens Corning acknowledges and agrees that the availability of funds (including the Term Facility) will not be a condition to the obligation of Owens Corning or Purchaser to consummate the transactions contemplated by the Arrangement Agreement.

Under the Arrangement Agreement, Owens Corning and Purchaser have agreed to use their commercially reasonable efforts to (a) maintain in effect the Credit Agreement (subject to any amendment, supplement, replacement, substitution, termination or other modification or waiver that is not prohibited by the Arrangement Agreement), (b) satisfy, or obtain a waiver thereof, on a timely basis all conditions to funding the Term Facility, (c) assuming that all conditions to funding contained in the Credit Agreement have been satisfied, consummate the funding of the Term Facility at or prior to the Effective Time, and (d) to the extent the Lenders do not fund the Tern Facility in accordance with the terms of the Credit Agreement, enforce their rights under the Credit Agreement.

Owens Corning has also agreed to keep Masonite reasonably informed with respect to all material activity concerning the status of the Term Facility and shall give Masonite notice of any material adverse change with respect to the Term Facility as promptly as practicable, including prompt notice (a) of the termination, repudiation, rescission, cancellation or expiration of the Credit Agreement, (b) of any breach or default (or any event or circumstance that, with or without notice, lapse of time or both, would reasonably be expected to give rise to any breach or default) by any party to the Credit Agreement, in each case of which Owens Corning or Purchaser becomes aware, (c) of the receipt of any written notice or other written communication, in each case received from any financing party with respect to any (i) breach of Owens Corning’s or Purchaser’s obligations under the Credit Agreement, or actual or potential default, termination or repudiation by any party to the Credit Agreement or (ii) material dispute between or among any parties to the Credit Agreement, and (d) of the receipt of any written notice or other written communication on the basis of which Owens Corning expects that a party to the Credit Agreement will fail to fund the Term Facility or is reducing the amount of the Term Facility.

Owens Corning has the right from time to time to amend, supplement, replace, substitute, terminate or otherwise modify or waive its rights under the Credit Agreement, including to (a) add lenders or similar entities who had not executed the Credit Agreement or (b) terminate or reduce any commitments under the Credit Agreement in order to obtain alternative sources of debt financing in lieu of all or a portion of the Term Facility; provided that no such amendment, supplement, replacement, substitution, termination, modification or waiver shall (i) reduce the aggregate amount of available Financing (including by increasing the amount of fees to be paid or original issue discount to less than the amount required to consummate the transactions contemplated by the Arrangement Agreement (when taken together with all cash on hand, available lines of credit and other sources of immediately available funds available to Owens Corning)), (ii) impose new or additional conditions precedent or expand upon the conditions precedent to the Financing as set forth in the existing Commitment Letter, (iii) adversely change the timing of the funding of the Financing in a manner that is reasonably expected to impair, delay or prevent the availability of all or a portion of the Financing or the consummation of the transactions contemplated by the Arrangement Agreement or (iv) otherwise materially adversely affect the ability of Owens Corning to consummate the transactions contemplated by the Arrangement Agreement.

In the event that any portion of the Term Facility necessary for Owens Corning to complete the Arrangement becomes unavailable on the terms and conditions contemplated by the Credit Agreement (other than as a result of Masonite’s breach of any provision of the Arrangement Agreement or failure to satisfy the conditions set forth in the Arrangement Agreement), Owens Corning has agreed to promptly notify Masonite and

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use commercially reasonable efforts to arrange and obtain, as promptly as practicable following the occurrence of such event, any such portion from alternative sources on terms that (a) taken as whole, are no more adverse to Owens Corning and Purchaser than the existing Commitment Letter (including after giving effect to the market flex provisions), (b) do not impose new or additional conditions precedent or expand upon the conditions precedent to the Financing set forth in the existing Commitment Letter and (c) do not reduce the aggregate amount of available Financing to less than the amount required to consummate the transactions contemplated by the Arrangement Agreement. Notwithstanding anything to the contrary contained in the Arrangement Agreement, in no event shall Owens Corning or its affiliates be required to pay any fees or any interest rates applicable to any alternative financing in excess of those contemplated by the Commitment Letter as in effect on the date hereof (including the market flex provisions) or agree to any term (including the market flex provisions) less favorable to Owens Corning than such term contained in the Commitment Letter as in effect on the date hereof(including the market flex provisions).

Closing and Effective Time

Unless another time or date is agreed to in writing by Masonite, Owens Corning, and Purchaser, the closing of the Arrangement will take place at the offices of Davis Polk & Wardwell LLP, and the Effective Time shall occur at 8:00 a.m. (New York City time) on the third business day after the satisfaction or waiver of all conditions to completion of the Arrangement (described below under the caption, “The Arrangement Agreement—Conditions to the Arrangement”) (excluding any conditions that, by their terms, cannot be satisfied until the Effective Date, but subject to the satisfaction or, where not prohibited, waiver of those conditions as of the Effective Date by the applicable party or parties for whose benefit such conditions exist), or on such other time and place as may be agreed upon by Masonite, Owens Corning, and Purchaser in writing.

From and after the Effective Time, the Plan of Arrangement shall have all of the effects provided by applicable law, including the Final Order and the BCBCA.

Canadian Federal Income Tax Considerations

The following is, as of the date hereof, a summary of the principal Canadian federal income tax considerations under the Tax Act and the Canadian Tax Regulations thereunder generally applicable to a Holder.

Masonite common shares will generally be considered capital property to a Holder unless the Holder holds or uses or is deemed to hold or use such Masonite common shares in the course of carrying on a business or the Holder acquired or is deemed to have acquired such Masonite common shares in a transaction or transactions considered to be an adventure or concern in the nature of trade.

This summary is based on the facts set out in this proxy statement, the current provisions of the Tax Act and the Canadian Tax Regulations in force as of the date hereof and counsel’s understanding of the current administrative policies and assessing practices of the Canada Revenue Agency (the “CRA”) made publicly available in writing prior to the date hereof. This summary also takes into account all specific proposals to amend the Tax Act or the Canadian Tax Regulations publicly announced by or on behalf of the Minister of Finance (Canada) prior to the date hereof (the “Tax Proposals”) and assumes that all Tax Proposals will be enacted in the form proposed. However, there can be no assurance that the Tax Proposals will be enacted in their current form, or at all. This summary, except for the Tax Proposals, does not take into account or anticipate any changes in law or the CRA’s administrative practice or policies, whether by legislative, regulatory, administrative or judicial decision or action, nor does it take into account or consider other federal or any provincial, territorial or foreign tax considerations, which may differ significantly from the Canadian federal income tax considerations described herein.

This summary is not applicable to a Holder: (a) that is a “financial institution” as defined in the Tax Act (for the purposes of the “mark-to-market” rules) contained in the Tax Act); (b) that is a “specified financial institution” as defined in the Tax Act; (c) an interest in which is or would be a “tax shelter investment” within the meaning of

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the Tax Act; (d) whose “functional currency” for the purposes of the Tax Act is the currency of a country other than Canada; (e) that has entered into or will enter into a “derivative forward agreement” or a “synthetic disposition arrangement” in respect of its Masonite common shares (each as defined in the Tax Act); (f) that (i) is a corporation resident in Canada and (ii) is, or becomes, or does not deal at arm’s length for purposes of the Tax Act with a corporation resident in Canada that is or becomes, as part of a transaction or event or series of transactions or events that includes the acquisition of the Masonite common shares, controlled by a non-resident person, or group of non-resident persons not dealing with each other at arm’s length, for the purposes of the foreign affiliate dumping rules in section 212.3 of the Tax Act; (g) that is exempt from tax under Part I of the Tax Act; or (h) that has acquired any Masonite common shares on the exercise of an option or pursuant to any other equity-based employment compensation plan or otherwise in the course of employment. All such Holders should consult their own tax advisors.

In addition, this summary does not address the tax considerations for holders of Masonite RSU Awards, Masonite PRSU Awards, or Masonite SAR Awards. Holders of such securities should consult with their own tax advisors.

This summary is of a general nature only and is not intended to be, nor should it be construed to be, legal or tax advice to any particular Holder. This summary is not exhaustive of all Canadian federal income tax considerations. Masonite shareholders are urged to consult their own tax advisors for advice regarding the income tax consequences to them of disposing of their Masonite common shares under the Arrangement, having regard to their own particular circumstances, and any other consequences to them of such transactions under Canadian federal, provincial, local and foreign tax laws.

Where an amount that is relevant in computing a Holder’s Canadian tax results is expressed in a currency other than Canadian currency (including adjusted cost base and proceeds of disposition), such amount must generally be converted to Canadian currency using the rate quoted by the Bank of Canada on the date such amount first arose, or using such other rate of exchange as is acceptable to the Minister of National Revenue (Canada).

Holders Resident in Canada

The following portion of the summary is generally applicable to a Resident Holder.

Certain Resident Holders whose Masonite common shares might not otherwise be considered capital property may, in certain circumstances, make an irrevocable election in accordance with Subsection 39(4) of the Tax Act to have the Masonite common shares and all other “Canadian securities” (as defined in the Tax Act) owned by such Resident Holder in the taxation year in which the election is made, and in all subsequent taxation years, deemed to be capital property. Resident Holders should consult with their own tax advisors if they contemplate making such an election.

Disposition of Shares under the Arrangement

Under the Arrangement, Resident Holders (other than a Resident Holder who validly exercises Dissent Rights (a “Dissenting Resident Holder”)) will be deemed to assign and transfer their Masonite common shares to Purchaser. Resident Holders will receive the applicable Per Share Arrangement Consideration, as may be adjusted, for each Masonite common share. As a result, the Resident Holder will generally realize a capital gain (or a capital loss) equal to the amount by which the aggregate Per Share Arrangement Consideration, as adjusted, exceeds (or is less than) the total of: (a) the aggregate adjusted cost base to the Resident Holder of such Masonite common shares immediately before the disposition; and (b) any reasonable costs of disposition. The taxation of capital gains and capital losses is discussed below under the caption “The Arrangement—Canadian Federal Income Tax Considerations—Holders Resident in Canada—Taxation of Capital Gains and Capital Losses.”

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Dissenting Resident Holders of Shares

A Dissenting Resident Holder will be deemed to have assigned and transferred such Dissenting Resident Holder’s Masonite common shares to Purchaser in consideration for a debt claim against Purchaser for the amount determined under Article 3 of the Plan of Arrangement. Such Dissenting Resident Holder may realize a capital gain (or a capital loss) equal to the amount by which such consideration (other than any portion thereof that is interest awarded by a court) exceeds (or is less than) the total of: (a) the aggregate adjusted cost base of to the Dissenting Resident Holder of such Masonite common shares immediately before the disposition; and (b) any reasonable costs of disposition. The taxation of capital gains and capital losses is discussed below under the caption “The Arrangement—Canadian Federal Income Tax Considerations—Holders Resident in Canada—Taxation of Capital Gains and Capital Losses.”

A Dissenting Resident Holder will be required to include in computing its income for a taxation year any interest awarded by a court in connection with the Arrangement.

Resident Holders who intend to dissent from the Arrangement are urged to consult their own tax advisors.

Taxation of Capital Gains and Capital Losses

Generally, a Resident Holder is required to include in computing its income for a taxation year one-half of the amount of any capital gain (a “taxable capital gain”) realized in such taxation year. Subject to and in accordance with the provisions of the Tax Act, a Resident Holder is generally required to deduct one-half of the amount of any capital loss (an “allowable capital loss”) realized in a taxation year from taxable capital gains realized by the Resident Holder in the year. Allowable capital losses for a taxation year in excess of taxable capital gains in that year may be carried back and deducted in any of the three preceding taxation years or carried forward and deducted in any subsequent taxation year against net taxable capital gains realized in such years to the extent and in the circumstances described in the Tax Act.

In the case of a Resident Holder that is a corporation, the amount of any capital loss otherwise resulting from the disposition of Masonite common shares may be reduced by the amount of dividends previously received or deemed to be received on the Masonite common shares or on shares substituted for such Masonite common shares, to the extent and under the circumstances prescribed in the Tax Act. Similar rules may apply where a Resident Holder is a partnership or trust of which a corporation, trust or partnership is a member or beneficiary, as the case may be. Resident Holders to whom these rules may be relevant should consult their own tax advisors.

Additional Refundable Tax

A Resident Holder, including a Dissenting Resident Holder, that is throughout the relevant taxation year a “Canadian-controlled private corporation” (as defined in the Tax Act) may be liable to pay an additional refundable tax on its “aggregate investment income” (as defined in the Tax Act) for the year, which will include taxable capital gains and interest. Certain Tax Proposals tabled in Parliament on November 28, 2023 as Bill C-59 would extend this additional tax and refund mechanism in respect of “aggregate investment income” to a Resident Holder that is a “substantive CCPC” (for purposes of the Tax Act and as defined in the Tax Proposals). Resident Holders should consult their own tax advisors in this regard.

Minimum Tax

Capital gains realized by a Resident Holder that is an individual or trust, other than certain specified trusts, may give rise to minimum tax under the Tax Act. Resident Holders should consult their own advisors with respect to the application of the minimum tax.

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Holders Not Resident in Canada

The following portion of the summary is generally applicable to a Non-Resident Holder. This summary does not apply to a Non-Resident Holder that carries on, or is deemed to carry on, an insurance business in Canada and elsewhere or that is an “authorized foreign bank” (as defined in the Tax Act). Such Non-Resident Holders should consult their own tax advisors.

Disposition of Shares under the Arrangement

A Non-Resident Holder will generally not be subject to tax under the Tax Act on any capital gain, or entitled to deduct any capital loss, realized on the disposition of Masonite common shares to Purchaser under the Arrangement unless such Masonite common shares constitute “taxable Canadian property” to the Non-Resident Holder for purposes of the Tax Act, and the Non-Resident Holder is not entitled to relief under an applicable income tax treaty or convention between Canada and the country in which the Non-Resident Holder is resident.

Provided that the Masonite common shares are listed on a “designated stock exchange” for the purposes of the Tax Act (which includes the NYSE) at the time of disposition, the Masonite common shares generally will not constitute taxable Canadian property to a Non-Resident Holder at such time unless, at any time during the sixty-month period immediately preceding the disposition, (a) 25% or more of the issued shares of any class or series of the capital stock of Masonite were owned by, or belonged to, any combination of (i) the Non-Resident Holder, (ii) Persons with whom the Non-Resident Holder does not deal at arm’s length, and (iii) partnerships in which the Non-Resident Holder or any Person described in (ii) holds an interest directly or indirectly through one or more partnerships; and (b) at such time, more than 50% of the fair market value of such Masonite common shares was derived, directly or indirectly from one or any combination of real or immovable property situated in Canada, “Canadian resource property” (as defined in the Tax Act), “timber resource property” (as defined in the Tax Act), or options or interests in respect of, interests in, or for civil law rights in such property, whether or not such property exists. Notwithstanding the foregoing, a Masonite common share may also be deemed to be taxable Canadian property to a Non-Resident Holder for purposes of the Tax Act in certain other circumstances. Non-Resident Holders should consult their own tax advisors as to whether their Masonite common shares constitute “taxable Canadian property” in their own particular circumstances.

If such Masonite common shares are taxable Canadian property to a Non-Resident Holder, a taxable capital gain resulting from the disposition of such Masonite common shares will not be included in computing the Non-Resident Holder’s income for purposes of the Tax Act if the Masonite common shares constitute “treaty-protected property” for the purposes of the Tax Act. Masonite common shares owned by a Non-Resident Holder will generally be treaty-protected property if the gain from the disposition of such Masonite common shares would, because of an applicable income tax treaty, be exempt from tax under the Tax Act.

In the event that Masonite common shares constitute taxable Canadian property and are not treaty-protected property to a particular Non-Resident Holder, the tax consequences as described above under the captions “The Arrangement—Canadian Federal Income Tax Considerations—Holders Resident in Canada—Disposition of Shares under the Arrangement” and “The Arrangement—Canadian Federal Income Tax Considerations—Holders Resident in Canada—Taxation of Capital Gains and Capital Losses” will generally apply.

Dissenting Non-Resident Holders

A Non-Resident Holder who validly exercises Dissent Rights (a “Dissenting Non-Resident Holder”) will be deemed to have assigned and transferred such Dissenting Non-Resident Holder’s Masonite common shares to Purchaser in consideration for a debt claim against Purchaser for the amount determined under Article 3 of the Plan of Arrangement.

A Dissenting Non-Resident Holder will generally not be subject to tax under the Tax Act on any capital gain or entitled to deduct any capital loss unless such Masonite common shares constitute “taxable Canadian

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property” to the Dissenting Non-Resident Holder and do not constitute “treaty-protected property.” See the discussion above under the caption “The Arrangement—Canadian Federal Income Tax Considerations—Holders Not Resident in Canada—Disposition of Shares under the Arrangement.”

Interest paid or deemed to have been paid to a Dissenting Non-Resident Holder will generally not be subject to Canadian withholding tax under the Tax Act, provided that such interest does not constitute participating debt interest.

Non-Resident Holders who intend to dissent from the Arrangement are urged to consult their own tax advisors.

U.S. Federal Income Tax Considerations

The following discussion is a summary of the U.S. federal income tax considerations of the Arrangement generally applicable to U.S. Holders (as defined below) of Masonite common shares whose Masonite common shares are converted into the right to receive cash pursuant to the Arrangement. This discussion is limited to U.S. Holders who hold their Masonite common share as “capital assets” within the meaning of Section 1221 of the Code (generally, property held for investment). This discussion is based upon the Internal Revenue Code of 1986, as amended (the “Code”), Treasury Regulations promulgated under the Code, rulings and other published positions of the Internal Revenue Service (the “IRS”) and judicial decisions, all as in effect on the date of this proxy statement and all of which are subject to change or differing interpretations at any time, possibly with retroactive effect. Any such change or differing interpretation could affect the accuracy of the statements and conclusions set forth in this discussion. No assurance can be given that the IRS would not assert, or that a court would not sustain, a position contrary to any of the tax considerations described in this discussion. No advance ruling has been or will be sought from the IRS regarding any matter discussed below.

This discussion is for general information purposes only and does not purport to be a complete analysis of all of the U.S. federal income tax considerations that may be relevant to particular holders in light of their particular facts and circumstances, or to Masonite shareholders subject to special rules under the U.S. federal income tax laws, including, for example,:

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This discussion does not address any U.S. federal tax considerations other than those pertaining to the income tax (such as estate, gift or other non-income tax consequences) or any state, local or foreign income or non-income tax considerations. In addition, this discussion does not address any considerations arising under the unearned income Medicare contribution tax pursuant to the Health Care and Education Reconciliation Act of 2010, or any considerations in respect of any withholding required pursuant to the Foreign Account Tax Compliance Act of 2010 (including the Treasury Regulations promulgated thereunder and intergovernmental agreements entered into in connection therewith and any laws, regulations or practices adopted in connection with any such agreement).

If a partnership (including an entity or arrangement treated as a partnership for U.S. federal income tax purposes) is a beneficial owner of Masonite common shares, the U.S. federal income tax treatment of a partner in such partnership generally will depend upon the status of the partner, the activities of the partner and the partnership and certain determinations made at the partner level. Accordingly, partners in partnerships holding Masonite common shares should consult their tax advisors as to the particular tax consequences to them of the Arrangement.

THIS DISCUSSION IS PROVIDED FOR GENERAL INFORMATIONAL PURPOSES ONLY. HOLDERS OF MASONITE COMMON SHARES SHOULD CONSULT THEIR OWN TAX ADVISORS WITH RESPECT TO THE SPECIFIC TAX CONSEQUENCES RELATING TO THE ARRANGEMENT IN LIGHT OF THEIR PARTICULAR CIRCUMSTANCES AND ANY CONSEQUENCES ARISING UNDER ANY U.S. FEDERAL, STATE, LOCAL, NON-U.S. OR OTHER TAX LAWS.

For purposes of this discussion, a “U.S. Holder” means a beneficial owner of Masonite common shares that is, for U.S. federal income tax purposes:

In general. Subject to the application of the PFIC rules described below, a U.S. Holder generally will recognize capital gain or loss on the exchange of Masonite common shares for cash pursuant to the Arrangement

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in an amount equal to the difference, if any, between the amount of cash received and the U.S. Holder’s adjusted tax basis in the Masonite common shares surrendered pursuant to the Arrangement. A U.S. Holder’s adjusted tax basis generally will equal the amount that such U.S. Holder paid for the Masonite common shares. A U.S. Holder’s gain or loss on the disposition of Masonite common shares generally will be characterized as capital gain or loss and will be long-term capital gain or loss if such U.S. Holder’s holding period in such shares is more than one year at the time of the completion of the Arrangement. Long-term capital gains of certain non-corporate holders, including individuals, are generally subject to U.S. federal income tax at preferential rates. The deductibility of capital losses is subject to limitations. If a U.S. Holder acquired different blocks of Masonite common shares at different times or different prices, such U.S. Holder must determine its adjusted tax basis and holding period separately with respect to each block of Masonite common shares.

PFIC Rules. Special U.S. federal income tax rules apply to U.S. persons owning stock in a “passive foreign investment company” (“PFIC”). A non-U.S. corporation, such as Masonite, will be considered a PFIC for any taxable year in which, (a) 75% or more of its gross income is “passive income” or (b) 50% or more of its assets (determined by value on the basis of a quarterly average) are considered “passive assets” (generally, assets that generate passive income).

Masonite believes that it has not been a PFIC for prior taxable years and does not expect to become a PFIC, but because this conclusion is a factual determination that must be made annually, there can be no assurance that Masonite will not be a PFIC for the current taxable year (or, if later, the year in which completion of the Arrangement occurs). If Masonite were to be classified as a PFIC for any taxable year during which a U.S. Holder held Masonite common shares, such classification could result in adverse tax consequences to such U.S. Holder, and U.S. federal income tax consequences different from those described above could apply to the receipt of cash by such U.S. Holder in exchange for Masonite ordinary shares pursuant to the Arrangement. In such event, gain realized by a U.S. Holder would in general not be treated as capital gain. Instead, a U.S. Holder generally would be treated as if it had realized such gain ratably over such U.S. Holder’s holding period in the Masonite common shares, and generally would be taxed at the highest applicable ordinary income tax rate in effect for each such year to which the gain is allocated, together with an interest charge in respect of the tax attributable to each such year. U.S. Holders should consult their tax advisors regarding the potential application of the PFIC rules to their Masonite common shares.

Information Reporting and Backup Withholding

Generally, information reporting requirements may apply in connection with payments made to U.S. Holders in connection with the Arrangement.

Backup withholding of tax (currently, at a rate of 24%) generally will apply to the proceeds received by a U.S. Holder pursuant to the Arrangement, unless the U.S. Holder provides the applicable withholding agent with a properly completed and executed IRS Form W-9 certifying such U.S. Holder’s correct taxpayer identification number and that such U.S. Holder is not subject to backup withholding, or otherwise establishes an exemption, and otherwise complies with the backup withholding rules. Backup withholding is not an additional tax. The amount of any backup withholding from a payment to a U.S. Holder generally will be allowed as a credit against such U.S. Holder’s U.S. federal income tax liability, if any, and may entitle such U.S. Holder to a refund, provided that the required information is timely furnished to the IRS.

MASONITE SHAREHOLDERS SHOULD CONSULT THEIR OWN TAX ADVISORS REGARDING THE TAX CONSEQUENCES OF THE ARRANGEMENT TO THEM IN LIGHT OF THEIR PARTICULAR CIRCUMSTANCES, INCLUDING THE APPLICABILITY AND EFFECT OF ANY STATE, LOCAL, NON-U.S. OR OTHER TAX LAWS.

Regulatory Approvals Required for the Arrangement

The Arrangement is subject to the requirements of the HSR Act, which prevents Owens Corning and Masonite from completing the transaction until required information and materials are furnished to the DOJ and

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the FTC and the HSR Act waiting period is terminated or expires. A transaction notifiable under the HSR Act may not be completed until the expiration of a 30-calendar-day waiting period following the parties’ filings of their respective HSR Act notification forms or the early termination of that waiting period. The parties may also choose to voluntarily re-start the initial 30-calendar-day waiting period by following certain prescribed procedures. After the expiration of the initial waiting period (or the re-started initial waiting period), the DOJ or the FTC may issue a Request for Additional Information and Documentary Material (referred to as a “second request”). If a second request is issued, the parties may not complete the Arrangement until they substantially comply with the second request and observe a second 30-calendar-day waiting period, unless the waiting period is terminated earlier, or the parties commit not to close for some additional period of time. Owens Corning and Masonite submitted the requisite notification and report forms under the HSR Act on February 23, 2024, and the waiting period will expire on March 25, 2024 at 11:59 p.m. Eastern time, unless it is extended by request for additional information or terminated earlier or if Owens Corning and Masonite pull and refile.

The Arrangement is also subject to the receipt of certain required regulatory clearances and approvals in other jurisdictions under applicable antitrust and foreign direct investment laws and regulations, including in Canada and Mexico. Owens Corning and Masonite submitted the requisite filings in Canada on February 21, 2024, February 23, 2024, and February 28, 2024, and in Mexico on February 23, 2024. In the United Kingdom, Owens Corning and Masonite also submitted a voluntary briefing paper to the CMA notifying the regulator of the Arrangement. The UK briefing paper was submitted to the CMA on February 21, 2024.

Although the parties expect that all required regulatory clearances will be obtained, the parties cannot assure you that these regulatory clearances will be timely obtained or obtained at all or that the granting of these regulatory clearances will not involve the imposition of additional conditions on the completion of the Arrangement, including the requirement to divest assets, create or modify contractual rights or obligations or enter into supply or services agreements. These conditions could result in the conditions to the Arrangement not being satisfied.

The Board of Directors unanimously recommends that you vote “FOR” this proposal.

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THE ARRANGEMENT AGREEMENT

The following describes the material provisions of the Arrangement Agreement, which is attached as Annex A to this proxy statement and is incorporated by reference herein. The summary of the material provisions of the Arrangement Agreement below and elsewhere in this proxy statement is qualified in its entirety by reference to the Arrangement Agreement. This summary does not purport to be complete and may not contain all of the information about the Arrangement Agreement that is important to you. Masonite encourages you to read carefully the Arrangement Agreement and the Plan of Arrangement, which is attached as Annex C to this proxy statement and is incorporated by reference herein, in their entirety before making any decisions regarding the Arrangement as they are the legal documents governing the Arrangement.

Explanatory Note Regarding the Arrangement Agreement

The Arrangement Agreement and this summary of its terms have been included to provide you with information regarding the terms of the Arrangement Agreement. Masonite is responsible for considering whether additional disclosure of material information is required to make the statements in this proxy statement not misleading. Factual disclosures about Masonite and Owens Corning contained in this proxy statement or Masonite’s or Owens Corning’s public reports filed with the SEC may supplement, update or modify the factual disclosures about Masonite or Owens Corning contained in the Arrangement Agreement and described in this summary. The representations, warranties and covenants made in the Arrangement Agreement by Masonite, Owens Corning and Purchaser are qualified and subject to important limitations agreed to by the parties to the Arrangement Agreement in connection with negotiating the terms of the Arrangement Agreement. In particular, in your review of the representations and warranties contained in the Arrangement Agreement and described in this summary, it is important to bear in mind that the representations and warranties were made solely for the benefit of the parties to the Arrangement Agreement, and were negotiated with the principal purpose of allocating risk between the parties to the Arrangement Agreement, rather than establishing matters as facts. The representations and warranties may also be subject to a contractual standard of materiality that may be different from that generally relevant to shareholders or applicable to reports and documents filed with the SEC, and in some cases are qualified by confidential disclosures that were made by each party to the other, which disclosures are not publicly disclosed. The representations and warranties in the Arrangement Agreement will not survive the completion of the Arrangement.

Investors should not rely on representations, warranties and covenants or any descriptions thereof as characterizations of the actual state of facts or condition of Masonite, Owens Corning, Purchaser or any of their respective subsidiaries or affiliates. Moreover, information concerning the subject matter of the representations and warranties may have changed since the date of the Arrangement Agreement. For the foregoing reasons, the representations, warranties and covenants or any descriptions of those provisions should not be read alone, but instead should be read together with the information provided elsewhere in this proxy statement and in the documents incorporated by reference into this proxy statement. See the section titled “Where You Can Find More Information.”

Structure of the Arrangement

The Arrangement will be implemented by way of a Court approved plan of arrangement under Division 5 of Part 9 of the BCBCA pursuant to the terms of the Arrangement Agreement. Upon completion of the Arrangement, Masonite will become an indirect wholly owned subsidiary of Owens Corning.

Timing of Closing

Unless another time or date is mutually agreed to in writing by Masonite, Owens Corning and Purchaser, the closing of the Arrangement will take place at 8:00 a.m. (New York City time) on the third business day after the satisfaction or waiver of the last of the conditions to completion of the Arrangement (excluding any conditions

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that, by their terms, cannot be satisfied until the Effective Date, but subject to the satisfaction or, where not prohibited, waiver of those conditions as of the Effective Date).

Arrangement Consideration

At the Effective Time, each Masonite common share issued and outstanding immediately prior to the Effective Time (other than Masonite common shares held by dissenting Masonite shareholders in respect of which Dissent Rights have been duly and validly exercised or Masonite common shares held by Masonite or any of its subsidiaries, Purchaser, or Owens Corning or any of its subsidiaries) will be deemed to be assigned and transferred by the holder thereof to Purchaser in exchange for the Per Share Arrangement Consideration, being $133.00 in cash, and (a) each registered holder of such Masonite common share shall cease to be the registered holder thereof and to have any rights as a Masonite shareholder other than the right to be paid the Per Share Arrangement Consideration, (b) the name of each such registered holder shall be removed from the register of Masonite shareholders maintained by or on behalf of Masonite, and (c) Purchaser shall be deemed to be the transferee of such Masonite common shares free and clear of all liens and shall be entered in the register of Masonite shareholders maintained by or on behalf of Masonite.

After the Arrangement is completed, you will have the right to receive the Per Share Arrangement Consideration in respect of each Masonite common share that you own immediately prior to the Effective Time (less any applicable withholding taxes), but you will no longer have any rights as a shareholder (except that shareholders who properly exercise their Dissent Rights will have a right to receive payment of the “fair value” of their shares as determined pursuant to a dissent proceeding, as contemplated by British Columbia law). For more information, see the section of this proxy statement captioned “Dissent Rights.”

Shares of Dissenting Masonite Shareholders

At the Effective Time, each Masonite common share held by a dissenting Masonite shareholder in respect of which Dissent Rights have been duly and validly exercised, will be deemed to have been assigned and transferred (free and clear of all liens) without any further act or formality by or on behalf of any dissenting Masonite shareholder, to Purchaser in consideration for a debt claim against Purchaser for the amount determined pursuant to Article 3 of the Plan of Arrangement, and: (i) such dissenting Masonite shareholders shall cease to be the holders of such Masonite common shares and to have any rights as holders of such Masonite common shares, other than the right to be paid fair value for such Masonite common shares, as set out in Article 3 of the Plan of Arrangement; (ii) such dissenting Masonite shareholders’ names shall be removed as the holders of such Masonite common shares from the registers of Masonite common shares maintained by or on behalf of Masonite; (iii) such dissenting Masonite shareholder will be deemed to have executed and delivered all consents, releases, assignments and waivers, statutory or otherwise, required to transfer and assign such Masonite common shares; and (iv) Purchaser shall be deemed to be the transferee of such Masonite common shares (free and clear of all liens) and shall be entered in the registers of the Masonite common shares maintained by or on behalf of Masonite.

For more information regarding appraisal rights, see the section captioned “Dissent Rights.” In addition, a copy of Division 2 of Part 8 of the BCBCA is attached as Annex G to this proxy statement.

Exchange and Payment Procedures

Upon the surrender by Masonite shareholders to the Depositary for cancellation of any certificate or certificates (including any direct registration statement advice) representing Masonite common shares (a “Certificate”) which immediately prior to the Effective Time represented outstanding Masonite common shares, together with a duly completed and executed Letter of Transmittal and such additional documents and instruments as the Depositary may reasonably require, such Masonite shareholder shall be entitled to receive in exchange therefor, and the Depositary shall deliver to such Masonite shareholder a check, wire or other form of

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immediately available funds representing the Per Share Arrangement Consideration which such Masonite shareholder has the right to receive under the Plan of Arrangement for such Masonite common shares, without interest, less any amounts withheld pursuant to the Plan of Arrangement, and any certificate so surrendered shall forthwith be canceled. Upon receipt of a customary “agent’s message” by the Depositary with respect to book-entry Masonite common shares, and such additional documents and instruments as the Depositary may reasonably require, the Depositary shall deliver to the holder of such book-entry Masonite common shares, a check, wire or other form of immediately available funds representing the Per Share Arrangement Consideration that such holder has the right to receive under the Arrangement for such book-entry Masonite common shares, less any amounts withheld pursuant to the Plan of Arrangement, and any book-entry Masonite common shares so surrendered shall forthwith be canceled.

Lost, Stolen or Destroyed Certificates

In the event any certificate which immediately prior to the Effective Time represented one or more outstanding Masonite common shares that were transferred pursuant to the Plan of Arrangement shall have been lost, stolen or destroyed, upon the making of an affidavit of that fact by the person claiming such certificate to be lost, stolen or destroyed, the Depositary will issue in exchange for such lost, stolen or destroyed certificate, a check, wire, or other form of immediately available funds for the Per Share Arrangement Consideration that such registered Masonite shareholder has the right to receive in accordance with the Plan of Arrangement and such registered Masonite shareholder’s Letter of Transmittal. When authorizing such payment in exchange for any lost, stolen, or destroyed certificate, the person to whom such cash is to be delivered shall as a condition precedent to the delivery of such payment, give a bond satisfactory to Purchaser and the Depositary (each acting reasonably) in such sum as Purchaser may direct, or otherwise indemnify Purchaser and Masonite in a manner satisfactory to Purchaser and Masonite (each acting reasonably) against any claim that may be made against Purchaser and Masonite with respect to the certificate alleged to have been lost, stolen or destroyed.

Dividends and Distributions

No Masonite shareholder shall be entitled to receive any consideration with respect to such Masonite common shares other than any cash payment to which such holder is entitled to receive in accordance with the Plan of Arrangement and no such registered Masonite shareholder will be entitled to receive any interest, dividends, premium, or other payment in connection therewith.

Rights of Masonite Shareholders Following the Effective Time; Transfers Following the Effective Time

From and after the Effective Time, and until surrendered to the Depositary in accordance with the Plan of Arrangement, each Certificate that immediately prior to the Effective Time represented Masonite common shares (other than Masonite common shares in respect of which Dissent Rights have been validly exercised and not withdrawn) shall be deemed after the Effective Time to represent only the right to receive upon such surrender the Per Share Arrangement Consideration which the holder is entitled to receive in lieu of such certificate, less any amounts withheld in accordance with the Plan of Arrangement. From and after the Effective Time, the stock transfer books of Masonite will be closed with respect to all Masonite common shares outstanding immediately prior to the Effective Time. 

Any such Certificate formerly representing Masonite common shares not duly surrendered on or before the sixth anniversary of the Effective Date shall cease to represent a claim by or interest of any former holder of Masonite common shares of any kind or nature against or in Masonite, Purchaser or Owens Corning. On such date, the Per Share Arrangement Consideration to which such former holder was entitled shall be deemed to have been surrendered to Purchaser, and shall be paid over by the Depositary to Purchaser or as directed by Purchaser.

Any payment made by way of check by the Depositary (or Masonite, if applicable) pursuant to the Plan of Arrangement that has not been deposited or has been returned to the Depositary (or Masonite) or that otherwise

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remains unclaimed, in each case, on the sixth anniversary of the Effective Date, and any right or claim to payment hereunder that remains outstanding on the sixth anniversary of the Effective Date shall cease to represent a right or claim of any kind or nature and the right of the holder to receive the applicable consideration for the Masonite common shares, Cash-Out RSUs, Cash-Out PRSUs and Masonite SAR Awards pursuant to the Plan of Arrangement shall terminate and be deemed to be surrendered and forfeited to Purchaser or Masonite, as applicable, for no consideration.

Withholding Rights

Masonite, Owens Corning, Purchaser and any of their respective subsidiaries will be entitled to deduct and withhold from any amounts otherwise payable pursuant to the Arrangement Agreement such amounts as are required to be deducted or withheld under the Tax Act, U.S. Tax Code or any other applicable tax law. Any amounts so deducted or withheld will, to the extent paid over to the appropriate taxing authority, be treated for all purposes of the Plan of Arrangement as having been paid to the person in respect of which such deduction or withholding was made.

Treatment of Masonite Equity Awards

Each Masonite RSU Award and each Masonite PRSU Award, that is held by an employee and does not vest at the Effective Time by its terms, will be exchanged at the Effective Time for a time-vesting Owens Corning RSU Award subject to substantially the same terms and conditions as applied to the corresponding Masonite RSU Award or Masonite PRSU Award immediately prior to the Effective Time, with the number of shares of Owens Corning common stock underlying such Owens Corning RSU Award equal to the product, rounded to the nearest whole share, obtained by multiplying (a) the number of Masonite common shares underlying the Masonite RSU Award or Masonite PRSU Award immediately prior to the Effective Time by (b) the Equity Award Exchange Ratio.

All Masonite RSU Awards and Masonite PRSU Awards that vest on or prior to the Effective Time or are held by an individual who is not an employee will be canceled at the Effective Time in exchange for the Per Share Arrangement Consideration in respect of each share of Masonite common stock subject to such Masonite RSU Award or Masonite PRSU Award. The number of Masonite common shares subject to Masonite PRSU Awards will be determined (x) with respect to performance periods that are complete as of the Effective Time, based on actual performance, and (y) with respect to performance periods that are incomplete as of the Effective Time, with performance goals deemed achieved at 122% of the target level (or, in the case of Masonite PRSU Awards that do not have a target level, such performance goals will be deemed fully satisfied).

Each Masonite SAR Award will be canceled at the Effective Time in exchange for a cash payment in respect of each share of Masonite common stock subject to such Masonite SAR Award equal to the excess (if any) of the Per Share Arrangement Consideration over the applicable exercise price.

Representations and Warranties

The Arrangement Agreement contains customary representations and warranties of the parties. These include representations and warranties of Masonite with respect to:

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The Arrangement Agreement also contains customary representations and warranties of Owens Corning and Purchaser, including among other things:

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The representations and warranties in the Arrangement Agreement do not survive the closing or termination of the Arrangement Agreement.

Certain of the representations and warranties made by the parties are qualified as to “knowledge,” “materiality” or “material adverse effect,” as defined in the Arrangement Agreement and described below.

Company Material Adverse Effect

A “material adverse effect” with respect to Masonite means any change, effect, development, circumstance, condition, fact, state of facts, event or occurrence that, individually or in the aggregate, has had or would reasonably be expected to have a material adverse effect on:

(a) the financial condition, assets, business or results of operations of Masonite and its subsidiaries, taken as a whole, excluding any change, effect, development, circumstance, condition, fact, state of facts, event or occurrence to the extent resulting from:

(i) changes or prospective changes in GAAP or the interpretation thereof;

(ii) general economic, political, regulatory, legal or tax conditions in the United States or any other country or region, including changes in financial, credit, securities or currency markets (including changes in interest or exchange rates) and the imposition or adjustment of tariffs;

(iii) conditions generally affecting any of the industries in which Masonite and its subsidiaries operate;

(iv) changes or prospective changes in applicable law or the interpretation thereof;

(v) geopolitical conditions, the outbreak or escalation of hostilities, acts of war, sabotage, terrorism, cyberattacks, protests, riots, strikes, global health conditions (including any epidemic, pandemic or disease outbreak) or natural disasters;

(vi) the execution, delivery and performance of the Arrangement Agreement or the announcement or completion of the transactions contemplated by the Arrangement Agreement or the identity of or any facts or circumstances relating to Owens Corning or any of its affiliates, including the impact of any of the foregoing on the business relationships, contractual or otherwise, of Masonite and any of its subsidiaries with customers, suppliers, service providers, employees, governmental authorities or any other business relationships resulting from any of the foregoing (provided that this clause (vi) will not apply to any representation or warranty to the extent such representation or warranty expressly purports to address, as applicable, the consequences resulting from the execution, delivery and performance of the Arrangement Agreement or the announcement or consummation of the transactions contemplated by the Arrangement Agreement, including as provided in Paragraph 4 of Schedule C to the Arrangement Agreement);

(vii) any actions requested in writing to be taken (or omitted to be taken) by or on behalf of Owens Corning or Purchaser;

(viii) any failure by Masonite or any of its subsidiaries to meet any internal or published budgets, projections, forecasts or predictions of financial performance or integration synergies for any period;

(ix) changes in the price or trading volume of the shares or any other securities of Masonite on the NYSE or any other market on which such securities are quoted for purchase and sale or changes in the credit ratings of Masonite (it being understood that any underlying facts giving rise or contributing to the failure or changes described in clauses (viii) or (ix) that are not otherwise excluded from the definition of a “material adverse effect” (with respect to Masonite and its Subsidiaries) may be taken into account in determining whether there has been a material adverse effect); or

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(x) any actions taken (or omitted to be taken) by Masonite or any of its subsidiaries that are required or expressly permitted to be taken (or omitted to be taken) pursuant to the Arrangement Agreement, including any actions required under the Arrangement Agreement to obtain any approvals, consents, registrations, permits, authorizations and other confirmations under applicable competition laws for the completion of the transactions contemplated by the Arrangement Agreement;

(xi) except, with respect to clauses (i), (ii), (iii), (iv) and (v) above, to the extent that such change, effect, development, circumstance, condition, fact, state of facts, event or occurrence is disproportionately adverse to Masonite and its subsidiaries relative to others in the industry or industries in which Masonite and its subsidiaries operate, in which case only the incremental disproportionate adverse change, effect, development, circumstance, condition, fact, state of facts, event or occurrence may be taken into account in determining whether a material adverse effect has occurred or would reasonably be expected to occur; or

(b) the ability of the relevant party to consummate the transactions contemplated by the Arrangement Agreement on or prior to the Outside Date.

Conduct of Businesses of Masonite Prior to Completion of the Arrangement

The Arrangement Agreement provides for certain restrictions on Masonite’s and its subsidiaries’ activities until the earlier of the Effective Time or the date (if any) the Arrangement Agreement is validly terminated. In general, except as required or expressly contemplated by the Arrangement Agreement, as required by applicable law or as consented to in writing by Owens Corning (which may not be unreasonably withheld, conditioned or delayed), subject to specified exceptions set forth in the Arrangement Agreement and the confidential schedules thereto, each of Masonite and its subsidiaries is required to use reasonable best efforts to (a) conduct its business in accordance with applicable law and in the ordinary course of business and (b) preserve intact in all material respects its current business operations, organization, ongoing businesses, exclusive licenses, permits and material business relationships with third parties, including vendors, suppliers, customers, partners and governmental authorities and maintain in full force and effect its insurance policies (including, for the avoidance of doubt, paying all premiums thereon and renewing or replacing such insurance policies on or prior to their expiration) in all material respects, in each case, consistent with past practice or customs in the industries in which Masonite and its subsidiaries conduct business.

In addition, except as required or expressly contemplated by the Arrangement Agreement, as required by applicable law or as consented to in writing by Owens Corning (which may not be unreasonably withheld, conditioned or delayed), subject to specified exceptions set forth in the Arrangement Agreement and the confidential schedules thereto, Masonite must not and must not permit any of its subsidiaries to:

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Interim Order, Shareholder Meeting and Board Recommendation

As promptly as practicable after the date of the Arrangement Agreement (and in no event no later than 20 business days after the date of the Arrangement Agreement, unless the parties otherwise agree), Masonite must prepare (with the assistance and cooperation of Owens Corning as reasonably requested by Masonite) and file or cause to be filed with the SEC a preliminary proxy statement related to the Special Meeting. Masonite must also cooperate in responding to any comments from the SEC and must use its reasonable best efforts to have the preliminary proxy statement cleared by the SEC as promptly as reasonably practicable after the filing.

Masonite must, as reasonably practicable after the date of the Arrangement Agreement (and in any event on or before the date that is the earliest of (a) the first business day that is eleven days after the initial filing of the preliminary proxy statement with the SEC if (i) the SEC staff does not notify Masonite that it will review the proxy statement by such time, or (ii) the SEC staff notifies Masonite that it will not review the proxy statement and (b) five days following the date that the SEC staff notifies Masonite that it has completed its review of proxy statement), apply in a manner reasonably acceptable to Owens Corning pursuant to Section 291 of the BCBCA and, in cooperation with Purchaser, prepare, file and diligently pursue and application for the Interim Order with the Court.

Masonite must, as soon as is reasonably practicable after the granting of the Interim Order, duly call and give notice of, and commence mailing of this proxy statement to holders of Masonite common shares as of the record date established for, a meeting of such holders to take place within 35 days following the first mailing of the proxy statement to Masonite shareholders (unless otherwise agreed by Masonite and Owens Corning), for purposes of submitting the Arrangement Resolution to its shareholders for adoption. The Special Meeting constitutes that required meeting of Masonite shareholders.

Subject to the ability of the Board of Directors to make an adverse recommendation change (as defined below), the Board of Directors is required to recommend to Masonite shareholders the adoption of the

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Arrangement Resolution, and Masonite is required to include that recommendation in this proxy statement and use reasonable best efforts to obtain from Masonite shareholders the approval of the Arrangement Resolution.

Under the terms of the Arrangement Agreement, Masonite may adjourn or postpone the Special Meeting (a) with the consent of Owens Corning or (b) to the extent Masonite believes in good faith (after consultation with outside legal counsel) that such adjournment or postponement is reasonably necessary (i) due to applicable law or request from the SEC, (ii) to allow reasonable additional time to solicit additional proxies necessary to obtain the Masonite shareholder approval or (iii) to allow reasonable additional time to ensure there are sufficient Masonite common shares represented and voting to constitute a quorum necessary to conduct the business of the Special Meeting. However, Masonite may not adjourn or postpone the Special Meeting more than once or for more than 20 business days in the aggregate without the prior written consent of Owens Corning.

Unless the Arrangement Agreement is validly terminated in accordance with its terms, Masonite must submit the Arrangement Resolution to its shareholders for adoption at the Special Meeting even if the Board of Directors has made an adverse recommendation change.

No Solicitation of Other Offers by Masonite

Under the terms of the Arrangement Agreement, subject to certain exceptions described below, Masonite has agreed that, from and after the date of the Arrangement Agreement until the earlier of the Effective Time or the date (if any) the Arrangement Agreement is validly terminated, Masonite will not, will cause its subsidiaries not to, and will cause its and their respective representatives not to, directly or indirectly:

In addition, under the Arrangement Agreement, Masonite has agreed that it will, and will cause its subsidiaries and its and their representatives to, cease immediately and cause to be terminated any and all

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existing activities, discussions or negotiations with any third party and its representatives conducted prior to the date of the Arrangement Agreement with respect to any acquisition proposal. Masonite also agreed to, within four business days after the date of the Arrangement Agreement, (a) request in writing that each person that had previously executed a confidentiality agreement in connection with its consideration of an acquisition proposal or potential acquisition proposal promptly destroy or return to Masonite all nonpublic information previously furnished by Masonite or any of its representatives to such person or any of its representatives in accordance with the terms of such confidentiality agreement and (b) terminate access to any physical or electronic data rooms relating to a possible acquisition proposal by such person and its representatives.

Notwithstanding the prohibitions described above, if prior to Masonite shareholders adopting the Arrangement Agreement, Masonite receives a bona fide written offer, inquiry, proposal or indication of interest from a third party with respect to an acquisition proposal that did not result from a material breach of Masonite’s non-solicitation obligations and the Board of Directors determines in good faith, after consultation with its outside legal counsel and financial advisors, constitutes or would reasonably be expected to lead to a superior proposal (as defined below), Masonite may engage in negotiations or discussions with such third party and its representatives and furnish to such third party or its representatives nonpublic information relating to Masonite or any of its subsidiaries, provided that Masonite also provides Owens Corning the same such nonpublic information (to the extent not previously provided to Owens Corning) substantially contemporaneously with (and in any event within 24 hours of) providing it to the third party.

Under the Arrangement Agreement, Masonite is obligated to notify Owens Corning promptly (and in any event within 24 hours) of any receipt by Masonite of any written acquisition proposal (including any bona fide written offer, inquiry, proposal or indication of interest with respect thereto) or any written amendment or modification to the material terms of any previously-received acquisition proposal or any material discussions with respect to any such acquisition proposal. The notice must include the identity of the person making such acquisition proposal and the material terms and conditions thereof, including unredacted copies of all material proposed transaction agreements (including financing commitments) and other material documents provided in connection therewith, including copies of all portions of written materials sent or provided to Masonite or any of its subsidiaries that describe such material terms and conditions. Masonite must also notify Owens Corning promptly (and in any event within 24 hours) of any request for nonpublic information relating to Masonite or any of its subsidiaries or for access to the business, properties, assets, books or records or personnel of Masonite or any of its subsidiaries by any third party that has notified Masonite that it is considering making, or has made, an acquisition proposal.

Without limiting the foregoing, Masonite must keep Owens Corning reasonably informed on a reasonably current basis (but in no event less often than once every 24 hours) of any changes (or any material discussions with respect thereto) to the status and material terms and conditions (along with unredacted copies of all material proposed transaction agreements (including financing commitments) and other material documents provided in connection therewith, including copies of all portions of written materials sent or provided to Masonite or any of its subsidiaries that describe such material terms and conditions thereof) of any acquisition proposal (or bona fide offer, inquiry, proposal or indication of interest with respect to thereto).

An “acquisition proposal” for purposes of the Arrangement Agreement means any bona fide third party offer or proposal relating to:

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A “superior proposal” for purposes of the Arrangement Agreement means a bona fide, unsolicited, written acquisition proposal, made after the date of the Arrangement Agreement (but substituting “50%” for all references to “20%” in the definition of such term) that the Board of Directors determines in good faith, after consultation with its outside legal counsel and financial advisors, is more favorable from a financial point of view to Masonite’s shareholders (solely in their capacity as such) than the transactions contemplated by the Arrangement Agreement, in each case, taking into consideration:

Change of Recommendation; Match Rights

The Arrangement Agreement requires the Board of Directors to recommend that Masonite shareholders vote to adopt the Arrangement Agreement and not make an adverse recommendation change as described above. Notwithstanding the foregoing, prior to Masonite shareholders adopting the Arrangement Agreement:

Prior to making an adverse recommendation change for any reason set forth above, Masonite must provide Owens Corning four business days’ prior written notice advising Masonite that it intends to make an adverse recommendation change or terminate the Arrangement Agreement. The notice must specify in reasonable detail the facts and circumstances relating to the adverse recommendation change due to an intervening event (as defined below), or the terms of the superior proposal (including the identity of the person or group making such proposal, a copy of any proposed definitive agreement and all other documentation and information described above under “—No Solicitation of Other Offers by Masonite”) for any adverse recommendation change due to a superior proposal.

In each case, Masonite must, and must cause its representatives to, negotiate in good faith (to the extent Owens Corning wishes to negotiate) during such four business day period any proposal by Owens Corning to amend the Arrangement Agreement in a manner that would eliminate the need for the Board of Directors to make an adverse recommendation change. The Board of Directors must make all of the required determinations regarding its fiduciary duties again at the end of such four business day period (after in good faith taking into account the amendments to the Arrangement Agreement proposed by Masonite) and may only make its adverse

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recommendation change if it determines at the end of such four business day period that the failure to make such adverse recommendation change would be inconsistent with its fiduciary duties under applicable law, and, in the case of superior proposal, that the acquisition proposal continues to constitute a superior proposal. With respect to any change of recommendation in response to a superior proposal, if there is any material amendment, revision or change to the terms of the then-existing superior proposal (including any revision to the form, amount or timing of payment of consideration proposed to be received by Masonite shareholders as a result of such superior proposal), Masonite must again comply with the obligations described in this paragraph, except that references to the applicable four business day period will be replaced with three business days.

An “intervening event” for purposes of the Arrangement Agreement is any event, fact, circumstance, development or occurrence that:

provided that in no event the following events will constitute or be taken into account in determining the existence of an intervening event: (a) Masonite meeting, failing to meet or exceeding any internal or published revenue or earnings forecasts or projections for any period or (b) changes in the market price or trading volume of Masonite common shares, provided that, in the case of the foregoing clauses (a) and (b), the underlying causes of such change, effect, development, circumstance, condition, fact, state of facts, event or occurrence that may be considered and taken into account in determining whether there has been an intervening event.

In addition, nothing in the Arrangement Agreement prohibits Masonite or the Board of Directors from (a) taking and disclosing to Masonite shareholders a position contemplated by Rule 14d-9 and Rule 14e-2(a) promulgated under the Exchange Act (or any similar communication to Masonite shareholders in connection with the making or amendment of a tender offer or exchange offer) or from making any legally required disclosure to shareholders with regard to the transactions contemplated by the Arrangement Agreement or an offer, inquiry, proposal or indication of interest with respect to an acquisition proposal (provided that neither Masonite nor the Board of Directors may make an adverse recommendation change unless permitted by the Arrangement Agreement), (b) issuing a “stop, look and listen” disclosure or similar communication of the type contemplated by Rule 14d-9(f) under the Exchange Act or (c) contacting and engaging in discussions with any person or group and their respective representatives who has made an offer, inquiry, proposal or indication of interest with respect to an acquisition proposal that was not solicited in breach of the Arrangement Agreement and was received by Masonite after the date of the Arrangement Agreement, solely for the purpose of clarifying such offer, inquiry, proposal or indication of interest and the terms thereof or informing such third party of the non-solicitation restrictions imposed by the Arrangement Agreement.

Access

The Arrangement Agreement provides that from the date of the Arrangement Agreement until the earlier of the Effective Time or the date (if any) the Arrangement Agreement is validly terminated, to the extent permitted by applicable law, Masonite will give Owens Corning and its representatives, upon reasonable notice, reasonable access during normal business hours to the offices, properties, assets, books and records and personnel (including employees and agents) of Masonite and its subsidiaries, will promptly furnish to Owens Corning and its representatives financial and operating data and other information that is reasonably requested and will instruct its representatives to cooperate reasonably with Owens Corning in its investigation of Masonite and its subsidiaries (provided that Masonite’s advisors will not be required to furnish any of their internal documents or materials). However, Masonite is not required to provide access if such access would jeopardize the health and

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safety of any of its representatives, relate to communications between Masonite and its advisors, violate applicable laws (including competition and privacy laws) or would result in disclosure of any information subject to attorney-client privilege, in the latter two cases subject to certain exceptions and requirements to make substitute arrangements.

Financing Assistance

Under the Arrangement Agreement, Masonite has agreed to use commercially reasonable efforts to provide, and use commercially reasonable efforts to cause its representatives and subsidiaries to use their respective commercially reasonable efforts to provide, all reasonable and customary cooperation that is reasonably requested by Owens Corning to assist Owens Corning in the arrangement of the Financing and the consummation of any exchange offer with respect to certain existing indebtedness of Masonite, subject to the terms set forth in the Arrangement Agreement (provided that such requested cooperation does not unreasonably interfere with the ongoing business or operations of Masonite and its subsidiaries), including using commercially reasonable efforts in connection with the following:

(a) reasonably cooperating with the marketing efforts or due diligence efforts in connection with the Financing and any Exchange Offer (as defined below);

(b) reasonably assisting Owens Corning in preparing (i) customary offering memoranda, rating agency presentations, road show materials, lender and investor presentations, confidential information memoranda, private placement memoranda, prospectuses and other similar documents for the Financing, and (ii) customary Debt Offer Documents for any Exchange Offer;

(c) delivering historical financial and other pertinent information regarding Masonite and its subsidiaries as may be reasonably requested by Owens Corning and that is customarily required for financings of the type contemplated by the Financing or for exchange offers of the type contemplated by the Exchange Offers;

(d) providing to Owens Corning’s legal counsel and its independent auditors such customary documents and other customary or pertinent information relating to the Company and its subsidiaries as may be reasonably requested in connection with their delivery of any customary legal opinions, negative assurance letters and customary comfort letters relating to the Financing and any Exchange Offer;

(e) causing Masonite’s independent auditors to provide customary cooperation with the Financing and any Exchange Offer;

(f) subject to customary confidentiality provisions and disclaimers, providing customary authorization letters with respect to the Financing, authorizing the distribution of information with respect to Masonite and its subsidiaries (but not, for the avoidance of doubt, Owens Corning, Purchaser and their respective subsidiaries) to prospective lenders or investors;

(g) delivering notices of prepayment within the time periods required by the Masonite credit agreements (which may be conditional upon the Effective Date), and using commercially reasonable efforts to obtain customary payoff letters, lien terminations and instructions of discharge and to give any other necessary notices to allow for the payoff, discharge and termination of the indebtedness under the Masonite credit agreements concurrently with the Effective Date; and

(h) permitting the reasonable use by Owens Corning of Masonite’s or any of its subsidiaries’ trademarks, service marks and logos as reasonably required in connection with the Financing and any Exchange Offer.

Treatment of Certain Masonite Indebtedness

Owens Corning or its affiliates will be permitted to (a) commence and conduct, in accordance with the terms of the indentures governing Masonite’s senior notes one or more offers to purchase and/or tender offers (each, a

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“Tender Offer” and collectively, the “Tender Offers”) and/or exchange offers (each, an “Exchange Offer” and collectively, the “Exchange Offers”), with respect to any or all of the outstanding aggregate principal amount of Masonite’s senior notes identified by Owens Corning or its affiliates to Masonite in writing on or after the date of the Arrangement Agreement, and (b) solicit the consent of the holders of Masonite’s senior notes (each, a “Consent Solicitation” and collectively, the “Consent Solicitations,” and, together with the Tender Offers and Exchange Offers, the “Debt Offers”) regarding certain proposed amendments to the indentures governing Masonite’s senior notes identified by Owens Corning or its affiliates to Masonite in writing on or after the date of the Arrangement Agreement.

Any Debt Offer will be made on such terms and conditions as are proposed by Owens Corning or its affiliates and which are permitted by the terms of the indentures governing Masonite’s senior notes, as applicable, and applicable law. Owens Corning shall consult with Masonite regarding the material terms and conditions of any Debt Offers, including the timing and commencement of any Debt Offers and any tender or consent deadlines. Owens Corning or its affiliates will provide Masonite with the necessary offer to purchase, offer to exchange, consent solicitation statement, letter of transmittal, press release (if any) or other related documents in connection with any Debt Offer (collectively, the “Debt Offer Documents”) a reasonable period of time in advance of commencing the applicable Debt Offer to allow Masonite and its counsel to review and comment on the related Debt Offer Documents, and Owens Corning shall give reasonable and good faith consideration to any comments made or input provided by Masonite and its legal counsel.

The closing (or, if applicable, effectiveness) of the Debt Offers shall not be consummated until the occurrence of the Effective Time and any such transaction shall be funded using consideration provided by Owens Corning; provided that the consummation of a Debt Offer with respect to Masonite’s senior notes will not be a condition to Owens Corning’s or its affiliates’ obligations to consummate the transactions contemplated by the Arrangement Agreement.

The Debt Offers will be conducted in compliance with the indentures governing Masonite’s senior notes and applicable law and Masonite will not be required to cooperate with respect to any Debt Offer that is not in compliance with the indentures governing Masonite’s senior notes and applicable laws. Masonite will use commercially reasonable efforts to provide, and will use commercially reasonable efforts to cause its representatives and subsidiaries to use their respective commercially reasonable efforts to provide, all reasonable and customary cooperation as may be reasonably requested by Owens Corning in connection with any Debt Offers; provided that such requested cooperation does not unreasonably interfere with the ongoing business or operations of Masonite and its subsidiaries; provided, further, that neither Masonite nor counsel for Masonite shall be required to furnish any certificates, legal opinions or negative assurance letters in connection with any Debt Offer or execute any other instruments or agreements in connection therewith subject to certain exceptions.

If, at any time prior to the completion of the Debt Offers, Masonite or any of its subsidiaries, on the one hand, or Owens Corning or any of its subsidiaries, on the other hand, discovers any information that should be set forth in an amendment or supplement to the Debt Offer Documents, so that the Debt Offer Documents shall not contain any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein, in light of circumstances under which they are made, not misleading, such party that discovers such information shall use commercially reasonable efforts to promptly notify the other party, and an appropriate amendment or supplement prepared by Owens Corning describing such information shall be disseminated to the holders of the applicable notes of Masonite outstanding under the applicable indenture.

Subject to the receipt of any requisite consents from the holders of Masonite’s senior notes, Masonite and its subsidiaries will execute one or more supplemental indentures to the indentures governing Masonite’s senior notes in accordance with the indentures governing Masonite’s senior notes (any such supplemental indenture, a “Supplemental Indenture” and, collectively, the “Supplemental Indentures”), amending the terms and provisions of the indentures governing Masonite’s senior notes as described in any applicable Debt Offer Documents as

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reasonably requested by Owens Corning or its affiliates, which the Supplemental Indentures will become operative no earlier than the Effective Time, and will use commercially reasonable efforts to cause the trustee under the indentures governing Masonite’s senior notes to enter into any such Supplemental Indentures, in each case, before or substantially simultaneously with the Effective Time as determined by Owens Corning or its affiliates; provided, however, that in no event will Masonite or any of its officers, directors or other representatives have any obligation to authorize, adopt or execute any amendments or other agreement that is not permitted under the indentures governing Masonite’s senior notes or applicable law or would become operative before the Effective Time. Masonite will use commercially reasonable efforts to provide, and will use commercially reasonable efforts to cause its representatives and subsidiaries to use their respective commercially reasonable efforts to provide, all reasonable and customary cooperation as may be reasonably requested by Owens Corning in connection with the execution of Supplemental Indentures; provided that such requested cooperation does not unreasonably interfere with the ongoing business or operations of Masonite and its subsidiaries.

If reasonably requested by Owens Corning or its affiliates, Masonite will use commercially reasonable efforts to provide, and will use commercially reasonable efforts to cause its legal counsel to provide, all customary certificates and legal opinions required by the trustee under the applicable Indenture in connection with the execution of any Supplemental Indentures to the extent (a) such certificates and legal opinions are required to be delivered before the Effective Time and (b) in the case of any such legal opinions, the trustee under the applicable Indenture requires an opinion of counsel to Masonite thereunder. Notwithstanding the foregoing, in no event will Masonite or its legal counsel be required to give any certificate or opinion with respect to a Debt Offer that, in the opinion of Masonite, its legal counsel or the trustee under the indentures governing Masonite’s senior notes, as applicable, does not comply with applicable laws or the indentures governing Masonite’s senior notes or would not be accurate in light of the facts and circumstances at the time delivered.

If requested by Owens Corning or any of its affiliates, in lieu of, in addition to or in combination with Owens Corning or its affiliates commencing any Debt Offer for Masonite’s senior notes, Masonite will, to the extent permitted by the indentures governing Masonite’s senior notes (a) issue one or more conditional notices of optional redemption for all or a portion of the outstanding aggregate principal amount of Masonite’s senior notes (which may be delivered at Owens Corning’s or Purchaser’s reasonable request in advance of the Effective Time so long as they are contingent upon the Effective Time (it being understood and agreed that they may also be contingent upon the occurrence of other events in addition to the Effective Time)), pursuant to the optional redemption provisions of the indentures governing Masonite’s senior notes, respectively, and (b) take any other actions reasonably requested by Owens Corning or Purchaser to facilitate the satisfaction and discharge of Masonite’s senior notes pursuant to the satisfaction and discharge provisions of the indentures governing Masonite’s senior notes and the other provisions of the indentures governing Masonite’s senior notes applicable thereto. If a conditional notice of optional redemption is given, Owens Corning or Purchaser will ensure that at the Effective Time, so long as the applicable conditions of such optional redemption are satisfied, Masonite has all funds necessary in connection with any such optional redemption. Masonite will use commercially reasonable efforts to provide, and will use commercially reasonable efforts to cause its representatives (including counsel, financial advisors and auditors) and subsidiaries to provide, all reasonable and customary cooperation as may be reasonably requested by Owens Corning in connection with the foregoing (provided that such requested cooperation does not unreasonably interfere with the ongoing business or operations of Masonite and its subsidiaries).

This proxy statement does not constitute a notice of repayment or redemption of any of the foregoing.

Limitations, Reimbursement and Indemnity

In connection with the foregoing, neither Masonite nor any of its subsidiaries will be required to take or permit the taking of any action that (a) would require Masonite, its subsidiaries or any persons who are directors

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or officers of Masonite or its subsidiaries to pass resolutions or consents to approve or authorize the Financing or any Debt Offers or execute or deliver any certificate, document, instrument or agreement or agree to any change or modification of any existing certificate, document, instrument or agreement, in each case, that is effective prior to the Effective Time, or that would be effective if the Effective Time does not occur, subject to certain exceptions, (b) would cause any representation or warranty in the Arrangement Agreement to be breached by Masonite or any of its subsidiaries (unless waived by Owens Corning), (c) would require Masonite or any of its subsidiaries to pay any commitment or other similar fee prior to the Effective Time or incur any other expense, liability or obligation in connection with the Financing or any Debt Offer, (d) would cause any director, officer or employee or shareholder of Masonite or any of its subsidiaries to incur any personal liability, (e) would cause any condition to the completion of the Arrangement to fail to be satisfied by the Effective Time or otherwise result in a breach of the Arrangement Agreement by Masonite, or (f) would result in a material violation or breach of, or a default under, any material contract to which Masonite or any of its subsidiaries is a party, the organizational documents of the Company or its subsidiaries or any applicable law, among certain other exceptions.

Owens Corning and Purchaser have agreed, on a joint and several basis, (a) promptly upon written request by Masonite, reimburse Masonite for all reasonable and documented out-of-pocket costs and expenses (including reasonable attorneys’ fees) incurred by Masonite or any of its subsidiaries in connection with the Financing or any Debt Offer or satisfying its financing assistance obligations, whether or not the Arrangement is consummated or this Agreement is terminated and (b) indemnify and hold harmless Masonite and its subsidiaries and their representative representatives from any and all losses or certain other claims suffered or incurred in connection with the Financing or certain actions in connection with existing indebtedness of Masonite, except in the case of this clause (b) such losses or other claims arise out of or result from the fraud, gross negligence or willful misconduct of Masonite or any of its subsidiaries or any of their respective representatives.

Employee Matters

For 12 months following the effective time (or through such earlier date that any continuing Masonite employee terminates employment), Owens Corning will cause each continuing Masonite employee (other than a continuing Masonite employee covered under a collective bargaining agreement) to receive (a) an annual rate of base salary or wages that is no less favorable than the annual rate of base salary or wages provided to such continuing Masonite employee as of immediately prior to the Effective Time, (b) target cash and equity incentive compensation opportunities (excluding any change in control, retention or similar payments) that, in the aggregate, are no less favorable than the target cash and equity incentive compensation opportunities provided to such continuing Masonite employee as of immediately prior to the Effective Time (but the form of any particular incentive compensation opportunity need not be the same), and (c) all other compensation and employee benefits that are substantially comparable in the aggregate to all other compensation and employee benefits provided to such continuing Masonite employee as of immediately prior to the Effective Time or that are provided to similarly situated employees of Owens Corning or its subsidiaries (including severance eligibility and paid time off, but excluding defined benefit pension and retiree medical or life insurance benefits). With respect to any continuing Masonite employee covered under a collective bargaining agreement, in lieu of the foregoing, Owens Corning or its subsidiaries will employ each such continuing Masonite employee on the terms and conditions consistent with the applicable collective bargaining agreement.

Directors’ and Officers’ Indemnification and Insurance

Under the Arrangement Agreement, for a period of six years after the Effective Time, Purchaser (or any of its successors or assigns) is required to honor all rights to indemnification or exculpation existing as of the date of the Arrangement Agreement in favor of present and former employees, officers and directors of Masonite and its subsidiaries.

Prior to the Effective Time, Masonite will, in consultation with Owens Corning, purchase (at Masonite’s expense) customary “tail” policies of directors’ and officers’ liability insurance for a period of six years after the

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Effective Time with respect to matters arising at or prior to the Effective Time providing protection no less favorable in the aggregate to the protection provided under Masonite’s and its subsidiaries’ existing policies in effect as of the date of the Arrangement Agreement, with a cost not in excess of 350% of the last aggregate annual premium paid by Masonite for directors’ and officers’ liability insurance for Masonite and its subsidiaries prior to the date of the Arrangement Agreement.

Other Covenants

The Arrangement Agreement contains additional agreements of Masonite, Owens Corning and Purchaser relating to, among other things:

Conditions to the Arrangement

The respective obligations of each party to effect the Arrangement are subject to the satisfaction or waiver of the following conditions:

The obligations of Purchaser to effect the Arrangement are subject to the satisfaction or waiver of the following additional conditions:

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The obligation of Masonite to effect the Arrangement is subject to the satisfaction or waiver of the following additional conditions:

Efforts to Obtain Regulatory Approvals and Clearances

Under the Arrangement Agreement, Masonite and Owens Corning are required to use reasonable best efforts to take, or cause to be taken (including by causing their controlled affiliates to take), all actions (including instituting or defending any legal proceeding), and to do, or cause to be done, all things necessary, proper or advisable under applicable law to consummate the transactions contemplated by the Arrangement Agreement prior to the Outside Date, including:

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In furtherance and not in limitation of the obligations described in the previous paragraph, the Arrangement Agreement requires Masonite and Owens Corning to:

Each of Masonite and Owens Corning agrees to take all actions reasonably necessary to resolve any objections by any governmental authority or third party and obtain any authorization, consent or approval of a governmental authority or to avoid or eliminate any impediments under the HSR Act or any such other competition law or foreign investment law as promptly as practicable so as to enable the consummation of the transactions contemplated by the Arrangement Agreement to occur no later than the Outside Date, including:

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However, Owens Corning is not required to (and Masonite may not, without Owens Corning’s prior written consent) offer, propose, negotiate, commit or agree to take or effect any regulatory action that would be, or would reasonably be expected to be, in the aggregate, material to Owens Corning and its subsidiaries (including Masonite and its subsidiaries), taken as a whole after giving effect to the Arrangement (“material” shall mean material measured on a scale relative only to the size of Masonite and its subsidiaries, taken as a whole); provided that any of the regulatory actions specified in the foregoing bullets will be conditioned upon the consummation of the Arrangement. Solely at Owens Corning’s request or with Owens Corning’s written consent, Masonite will agree to divest, hold separate or otherwise take or commit to take any action that limits its freedom of action with respect to, or its ability to retain, any of its or its subsidiaries businesses, services or assets; provided that any such action shall be conditioned upon the consummation of the Arrangement.

Under the Arrangement Agreement, Masonite and Owens Corning also agree to:

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Without limiting Owens Corning’s obligation described above to use reasonable best efforts to take all steps as may be necessary, subject to the limitations described above, to obtain all required approvals, Masonite and Owens Corning have agreed that Owens Corning will control the ultimate strategy and timing with respect to the antitrust matters described in this section, provided that Owens Corning reasonably consults with and considers in good faith any comments of Masonite or its representatives relating to such strategy and provided that Owens Corning will not extend any waiting period under the HSR Act or under any other competition or foreign investment law or enter into any agreement with any governmental authority not to consummate the transactions contemplated by the Arrangement Agreement without Masonite’s prior written consent, which, in the case of the extending any such waiting period, will not be unreasonably withheld.

Termination of the Arrangement Agreement

Termination by Masonite or Owens Corning

The Arrangement Agreement may be terminated at any time before the Effective Time:

Termination by Masonite

The Arrangement Agreement may be terminated at any time before the Effective Time by Masonite if:

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Termination by Owens Corning

The Arrangement Agreement may be terminated at any time before the effective time by Owens Corning if:

Termination Fees and Expenses

Expenses

Except as otherwise expressly provided in the Arrangement Agreement and Plan of Arrangement (including the termination fees described below), all costs and expenses incurred in connection with the Arrangement Agreement and Plan of Arrangement and the transactions contemplated thereby will be paid by the party incurring the cost or expense, whether or not the Arrangement is consummated.

Masonite Termination Fee

The Arrangement Agreement provides that Masonite will pay Owens Corning a termination fee of $75 million if:

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In no event will Masonite be obligated to pay the termination fee on more than one occasion. Except in the case of fraud or material and willful breach of the Arrangement Agreement by Masonite, the receipt by Owens Corning of the Masonite termination fee will be the sole and exclusive remedy of Owens Corning and Purchaser in connection with the Arrangement Agreement and neither Owens Corning nor Purchaser will seek to obtain any recovery, judgment, or damages of any kind, including consequential, indirect, or punitive damages, against Masonite or any of Masonite’s subsidiaries or any of their respective directors, officers, employees, partners, managers, members, stockholders, affiliates or representatives in connection with the Arrangement Agreement.

Owens Corning Termination Fee

The Arrangement Agreement provides that Owens Corning will pay Masonite a termination fee of $150 million if:

In no event will Owens Corning be obligated to pay the termination fee on more than one occasion. Except in the case of fraud or material and willful breach of the Arrangement Agreement by Owens Corning or Purchaser, the receipt by Masonite of the Owens Corning termination fee will be the sole and exclusive remedy of Masonite in connection with the Arrangement Agreement and Masonite will not seek to obtain any recovery, judgment, or damages of any kind, including consequential, indirect, or punitive damages, against Owens Corning, Purchaser, any of their respective subsidiaries or any of their respective directors, officers, employees, partners, managers, members, stockholders, affiliates or representatives in connection with the Arrangement Agreement.

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Effect of Termination

In the event of termination of the Arrangement Agreement in accordance with the terms of the Arrangement Agreement, the Arrangement Agreement will become void (except that provisions relating to the effect of termination, payment of the termination fees, public announcements relating to the Arrangement and certain other provisions, together with the confidentiality agreement between Owens Corning and Masonite, will survive any such termination), and there will be no liability on the part of any of the parties, except that no party will be relieved of liability for fraud or any material and willful breach of the Arrangement Agreement.

Governing Law

The Arrangement Agreement is governed by and interpreted and enforced in accordance with the laws of the Province of British Columbia and the federal laws of Canada.

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PRINCIPAL LEGAL MATTERS

Court Approval and Completion of the Arrangement

The Arrangement requires approval by the Court under Section 291 of the BCBCA. Prior to the mailing of this proxy statement, Masonite obtained the Interim Order providing for the calling and holding of the Special Meeting, the Dissent Rights and other procedural matters. A copy of the Interim Order is attached hereto as Annex D of this proxy statement. A copy of the notice of hearing of petition in respect of the hearing of Masonite’s application for the Final Order is attached hereto as Annex H.

Subject to the approval of the Arrangement Resolution at the Special Meeting and the terms of the Interim Order, the hearing of Masonite’s application for the Final Order is expected to take place on [ ], 2024 at the Courthouse at 800 Smithe Street, Vancouver, British Columbia, or at any other date and time by any method as the Court may direct and the parties agree. Any Masonite shareholder or interested party who wishes to participate, appear, to be represented, and to present evidence or arguments at the hearing must file and serve a Response to Petition and satisfy the other requirements of the Court, as directed in the Interim Order attached hereto as Annex D and as the Court may direct in the future. In the event that the hearing is postponed, adjourned or rescheduled then, subject to further direction of the Court, only those persons having previously served a Response to Petition in compliance with the Interim Order will be given notice of the new date. Participation in the hearing of Masonite’s application for the Final Order, including who may participate and present evidence or argument and the procedure for doing so, is subject to the terms of the Interim Order and any subsequent direction of the Court.

The Court has broad discretion under the BCBCA when making orders with respect to arrangements. The Court will consider, among other things, the fairness and reasonableness of the Arrangement and the rights of every person affected. The Court may approve the Arrangement either as proposed or as amended in any manner the Court may direct, subject to compliance with such terms and conditions, if any, as the Court deems fit. If any such amendments are made, depending on the nature of the amendments, the parties to the Arrangement Agreement may not be obligated to complete the transactions contemplated in the Arrangement Agreement. For more information, see the section of this proxy statement captioned “The Arrangement Agreement—Conditions to the Arrangement.”

Assuming that the Final Order is granted, and the other conditions precedent to the completion of the Arrangement are satisfied or waived to the extent legally permissible, the Arrangement will become effective on the third business day following the satisfaction or waiver of the last of the conditions to the completion of the Arrangement set forth in the Arrangement Agreement. See the section of this proxy statement captioned “The Arrangement—Closing and Effective Time.”

Although Masonite’s, Owens Corning’s and Purchaser’s objective is to have the Effective Date occur as soon as possible after the Special Meeting, the Effective Date could be delayed for a number of reasons, including, but not limited to, an objection before the Court at the hearing of the application for the Final Order or any delay in satisfying the other conditions to the completion of the Arrangement, including obtaining applicable regulatory approvals and clearances.

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PROPOSAL 2: THE COMPENSATION PROPOSAL

Overview

Under Section 14A of the Exchange Act and the applicable SEC rules issued thereunder, Masonite is required to submit a proposal to our shareholders to approve, on an advisory (non-binding) basis, the compensation that may be paid or become payable to Masonite’s named executive officers that is based on or otherwise relates to the Arrangement Agreement and the transactions contemplated by the Arrangement Agreement (the “Compensation Proposal”). This compensation is summarized in the section captioned “The Arrangement—Interests of Masonite’s Executive Officers and Directors in the Arrangement—Quantification of Potential Payments and Benefits to Masonite’s Named Executive Officers in Connection with the Arrangement.” The Board of Directors encourages you to review carefully the named executive officer Arrangement-related compensation information disclosed in this proxy statement. Accordingly, Masonite is asking you to approve the following resolution:

RESOLVED, that the shareholders of Masonite approve, on a non-binding, advisory basis the compensation that will or may become payable to Masonite’s named executive officers that is based on or otherwise relates to the Arrangement as disclosed pursuant to Item 402(t) of Regulation S-K in the section captioned “The Arrangement—Interests of Masonite’s Executive Officers and Directors in the Arrangement—Quantification of Potential Payments and Benefits to Masonite’s Named Executive Officers in Connection with the Arrangement.”

Vote Require for Approval

The vote on this Compensation Proposal is a vote separate and apart from the vote on the Arrangement Resolution and the Adjournment Proposal. Accordingly, you may vote to approve the Arrangement Resolution and/or the Adjournment Proposal and vote not to approve the Compensation Proposal and vice versa. Because the vote on the Compensation Proposal is advisory only, it will not be binding on Masonite. Accordingly, if the Arrangement Resolution is approved and the Arrangement is completed, the compensation will be payable, subject only to the conditions applicable thereto, regardless of the outcome of the vote on this Compensation Proposal. The approval of the Compensation Proposal by Masonite shareholders is not a condition to the completion of the Arrangement.

The affirmative vote of at least a majority of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting is required to approve, on an advisory (non-binding) basis, the Compensation Proposal, assuming a quorum is present. Each Masonite common share outstanding on the record date of the Special Meeting is entitled to one vote on this proposal. If a quorum is present at the Special Meeting, failures to vote, abstentions and broker non-votes will have no effect on the vote for this proposal.

Recommendation of the Board of Directors

The Board of Directors unanimously recommends that Masonite shareholders vote “FOR” the Compensation Proposal.

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PROPOSAL 3: THE ADJOURNMENT PROPOSAL

Overview

We are asking you to approve a proposal to adjourn the Special Meeting to a later date or dates if necessary or appropriate to solicit additional proxies if there are insufficient votes to adopt the Arrangement Agreement at the time of the Special Meeting (the “Adjournment Proposal”). If shareholders approve the Adjournment Proposal, we could adjourn the Special Meeting and any adjourned session of the Special Meeting and use the additional time to solicit additional proxies, including soliciting proxies from Masonite shareholders that have previously returned properly executed proxies voting against the Arrangement Resolution. Among other things, approval of the Adjournment Proposal could mean that, even if we had received proxies representing a sufficient number of votes against Arrangement Resolution such that the Arrangement Resolution would be defeated, we could adjourn the Special Meeting without a vote on the Arrangement Resolution and seek to convince the holders of those shares to change their votes to votes in favor of the Arrangement Resolution. Additionally, we may seek to adjourn the Special Meeting if a quorum is not present or otherwise at the discretion of the chairman of the Special Meeting.

Vote Required for Approval

The vote on this Adjournment Proposal is a vote separate and apart from the vote on the Arrangement Resolution and the Compensation Proposal. Accordingly, you may vote to approve the Arrangement Resolution and/or the Compensation Proposal and vote not to approve the Adjournment Proposal and vice versa. The approval of the Adjournment Proposal by Masonite shareholders is not a condition to the completion of the Arrangement.

The affirmative vote of at least a majority of the votes cast by Masonite shareholders present in person or represented by proxy at the Special Meeting is required to approve, on an advisory (non-binding) basis, the Adjournment Proposal, assuming a quorum is present. Each Masonite common share outstanding on the record date of the Special Meeting is entitled to one vote on this proposal. If a quorum is present at the Special Meeting, failures to vote, abstentions and broker non-votes will have no effect on the vote for this proposal.

Recommendation of the Board of Directors

The Board of Directors unanimously recommends that Masonite shareholders vote “FOR” the Adjournment Proposal.

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SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT

The following table sets forth the number of Masonite common shares beneficially owned as of the close of business on March 5, 2024, by (i) each of those known to Masonite to be the beneficial owner of more than 5% of the total issued and outstanding number of Masonite common shares, (ii) each director of Masonite, (iii) the named executive officers of Masonite, and (iv) all directors and all named executive officers of Masonite as a group.

Percentage of beneficial ownership provided in the tables is based on 21,975,800 outstanding Masonite common shares as of the close of business on March 5, 2024, unless otherwise indicated in a footnote below (and in that case based upon SEC filings made on behalf of such owners). Beneficial ownership is determined in accordance with the rules of the SEC and generally includes voting or investment power with respect to securities.

The only Masonite shareholders known to Masonite to beneficially own more than 5% of any class of Masonite’s voting securities are:

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DIRECTORS AND EXECUTIVE OFFICERS