Compagnie de Saint-Gobain

Pre-Annual General Meeting Information • May 5, 2023

This text is a free translation from the French language and is supplied solely for information purposes. Only the original version in the French language has legal force.

DESCRIPTION OF THE SHARE BUY-BACK PROGRAM TO BE SUBMITTED TO THE ORDINARY AND EXTRAORDINARY GENERAL MEETING CONVENED TO BE HELD ON JUNE 8, 2023 (THIRTEENTH RESOLUTION)

In accordance with Articles 241-1 et seq. of the French Financial Markets Authority's (Autorité des marchés financiers) General Regulations, this description aims to indicate the objectives, terms and conditions of the share buy-back program of COMPAGNIE DE SAINT-GOBAIN (the "Company") to be submitted for approval to the Ordinary and Extraordinary General Shareholders' Meeting convened to be held on June 8, 2023.

The Board of Directors wishes that the Company renews its share buy-back program. To this end, it will be proposed to the Ordinary and Extraordinary General Shareholders' Meeting to be held on June 8, 2023 to authorize, as it does every year, through the 13 th resolution, the implementation of a new share buy-back program to be established in accordance with the provisions of Articles L. 22-10-62 et seq. of the French Commercial Code, the European Regulation (EU) No. 596/2014 dated April 16, 2014, and the delegated regulations taken for its application, the French Financial Markets Authority's General Regulations and the market practice authorized by the latter. This authorization would supersede and replace the one granted in the 16 th resolution of the Ordinary and Extraordinary General Meeting held on June 2, 2022, for the unused portion and the unexpired period.

Shares may be purchased, sold, transferred or exchanged at any time, except during a public tender offer period involving the Company's shares, and by any means, provided that laws and regulations in force are complied with, on one or more occasions, on or off the stock market, over the counter, in whole or in part in blocks of shares, by public tender offer in cash or in shares, by using options or derivatives, either directly or indirectly through the intermediation of an investment services provider, or in any other way.

The Company's shares are listed on the Euronext Paris regulated market.

I. Date of the General Meeting called to authorize the share buy-back program

The new share buy-back program will be submitted for approval to the Ordinary and Extraordinary General Shareholders' Meeting of June 8, 2023.

II. Number of shares and interest held by the Company

As of May 4, 2023, the Company held, directly or indirectly, 8,468,749 of its own shares, representing 1.64% of the Company's share capital.

Compagnie de Saint-Gobain

III. Split of the shares held by the Company per objective

As of May 4, 2023:

• 1,943,700 shares were allocated to the coverage of performance shares plans and other forms of allotment to employees (including purchase stock options);
• 6,463,525 shares are held for the purpose of cancellation; and
• 61,524 shares were allocated, for purposes of stabilizing the Saint-Gobain share price, to the liquidity agreement entered into with Exane BNP Paribas on June 20, 2019, in compliance with the charter of the French Association Française des Marchés Financiers recognized by the French Financial Markets Authority.

IV. Purposes of the new share buy-back program

Under the new share buy-back program that will be submitted for approval to the Ordinary and Extraordinary General Shareholders' Meeting of June 8, 2023, the Company is considering repurchasing its shares, or having its shares repurchased, for purposes of:

• − the free allocation of shares, the grant of stock options, the allocation or sale of shares under employee savings plans or other similar plans;
• − offsetting the potential dilutive impact of free allocation of shares, of the granting of stock options, or of subscription by employees as part of the employee savings plans or other similar plans;
• − delivering shares upon exercise of the rights attaching to securities giving access in any way, in particular through the exercise of rights attached to securities giving access to the share capital by redemption, conversion, exchange, presentation of a warrant, to the allocation of Company shares;
• − the management of the market of the Company share under liquidity agreements entered into with an independent investment services provider in compliance with the code of ethics recognized by the French Financial Markets Authority;
• − the cancellation of shares subject to the adoption by the Ordinary and Extraordinary General Shareholders' Meeting of June 8, 2023 of the twenty-second resolution;
• − the implementation of any market practice that may become authorized by the French Financial Markets Authority and, more generally, with a view to carrying out any other transaction that complies with the regulations in force.

V. Maximum proportion of share capital to be purchased, maximum purchase price and maximum number of and type of securities that may be acquired under the new share buyback program

The maximum proportion of the Company's share capital that might be bought back under the new share buy-back program would be 10% of the total number of shares comprising the Company's share capital as of the date of the Ordinary and Extraordinary General Meeting to be held on June 8, 2023. The number of shares acquired with a view to retaining them for subsequently delivering them as payment or in exchange as part of mergers, split-ups or contributions would not exceed 5% of the Company's share capital at such date. In accordance with Article L. 225-210 of the French Commercial Code, the number of shares that the Company can hold at any time may not exceed 10% of the shares comprising the Company's share capital.

The maximum purchase price under the new share buy-back program would be €100 per share, it being specified that such price might be adjusted in the event of transactions on the Company's share capital, in particular an increase in capital through the capitalization of reserves, the allocation of free shares, a stock split or reverse stock split, the distribution of reserves or any other assets, impairment of share capital or any other transaction involving share capital or shareholders' equity, the above-mentioned maximum price will be adjusted to take into account the impact of these transactions on the stock value.

The Company would only be authorized to repurchase ordinary shares.

For information purposes, 51,579,102 shares could be bought back (10% of the share capital based on the share capital as of May 4, 2023).

VI. Duration of the new share buy-back program

In accordance with the thirteenth resolution that will be submitted for approval at the Ordinary and Extraordinary General Shareholders' Meeting to be held on June 8, 2023, the new share buy-back program would be implemented over an eighteen-month period following the date of the Meeting, i.e., until December 8, 2024.

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In accordance with the terms of Article 241-2, II of the French Financial Markets Authority's General Regulations, during the implementation of the share buy-back program, any significant alteration of any of the information listed in sections IV, V and VI above will be made public in compliance with the terms set forth in Article 221-3 of the General Regulations.