THIS ANNOUNCEMENT RELATES TO THE DISCLOSURE OF INFORMATION THAT QUALIFIED OR MAY HAVE QUALIFIED AS INSIDE INFORMATION WITHIN THE MEANING OF ARTICLE 7(1) OF THE MARKET ABUSE REGULATION (EU) 596/2014. AS IT FORMS PART OF UK DOMESTIC LAW BY VIRTUE OF THE EUROPEAN UNION (WITHDRAWAL) ACT 2018

NOT FOR DISTRIBUTION IN OR INTO OR TO ANY PERSON LOCATED OR RESIDENT IN THE UNITED STATES, ITS TERRITORIES AND POSSESSIONS (INCLUDING PUERTO RICO, THE U.S. VIRGIN ISLANDS, GUAM, AMERICAN SAMOA, WAKE ISLAND AND THE NORTHERN MARIANA ISLANDS), ANY STATE OF THE UNITED STATES OR THE DISTRICT OF COLUMBIA (the United States), OR TO PERSONS WHO ARE "U.S. PERSONS" AS DEFINED IN, AND IN RELIANCE ON, REGULATION S UNDER THE U.S. SECURITIES ACT OF 1933, AS AMENDED (each, a U.S. Person), OR INTO ANY OTHER JURISDICTION WHERE IT IS UNLAWFUL TO DISTRIBUTE THIS ANNOUNCEMENT.

16 May 2022

COMPAGNIE DE SAINT-GOBAIN ANNOUNCES FINAL RESULTS OF THE TENDER OFFER

On 6 May 2022, Compagnie de Saint-Gobain (the Offeror) launched an invitation to holders of its outstanding GBP300,000,000 5.625 per cent. notes due November 2024 (ISIN: XS0274270817) (the Notes), to tender their Notes for purchase by the Offeror for cash (the Offer), subject to applicable offer and distribution restrictions.

Capitalised terms used and not otherwise defined in this announcement have the meanings given in the Tender Offer Memorandum dated 6 May 2022 (the Tender Offer Memorandum).

The Offeror announces that it will accept for purchase in cash an aggregate principal amount of the Notes validly tendered pursuant to the Offer equal to GBP183,600,000. The final results of the Offer are as follows:

The Offer remains subject to the conditions and restrictions set out in the Tender Offer Memorandum.

The expected Tender Offer Settlement Date is 18 May 2022.

Full details concerning the Offer are set out in the Tender Offer Memorandum.

Questions and requests for assistance in connection with the Offer may be directed to the Dealer Manager and the Tender Agent, the contact details for both of which are set out below.

NatWest Markets N.V. (Telephone +33-173249880; Attention: Liability Management; Email: liabilitymanagement@natwestmarkets.com) is acting as Dealer Manager and Kroll Issuer Services Limited (Telephone: +44 20 7704 0880; Attention: Thomas Choquet; Email: saintgobain@is.kroll.com) is acting as Tender Agent.

This announcement is released by Compagnie de Saint-Gobain and contains information that qualified or may have qualified as inside information for the purposes of Article 7 of the Market Abuse Regulation (EU) 596/2014 as it forms part of UK domestic law by virtue of the European Union (Withdrawal) Act 2018 (UK MAR), encompassing information relating to the Offer described above. For the purposes of UK MAR and Article 2 of Commission Implementing Regulation (EU) 2016/1055; this announcement is made by Paul Thomson, Directeur Droit des Financements of Compagnie de Saint-Gobain.

DISCLAIMER This announcement must be read in conjunction with the Tender Offer Memorandum. No offer or invitation to acquire or sell any securities is being made pursuant to this announcement. The Dealer Manager does not take responsibility for the contents of this announcement. The distribution of this announcement and the Tender Offer Memorandum in certain jurisdictions may be restricted by law. Persons into whose possession this announcement and/or the Tender Offer Memorandum come into are required by each of the Offeror, the Dealer Manager and the Tender Agent to inform themselves about, and to observe, any such restrictions.

The Offer has not been and will not be registered under the United States Securities Act of 1933, as amended (the Securities Act) or with any securities regulatory authority of any state or other jurisdiction of the United States and the Notes may not be tendered in the Offer within the United States or to, or for the account or benefit of, U.S. Persons except pursuant to an effective registration statement under the Securities Act or an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act, in each case in accordance with any applicable securities laws of any state of the United States.