Results of Operations and Financial Condition On August 5, 2026, Owens Corning (the "Company") issued a press release announcing its financial results for the quarter ended June 30, 2026. Exhibit 99.1 contains certain financial measures that are considered "non-GAAP financial measures" as defined in the federal securities laws and contains an explanation and, as applicable, a reconciliation of these non-GAAP financial measures to their most directly comparable financial measures calculated an…

Chief Financial Officer — Jonathan M. Collins: The company hired a new CFO from an external source with significant experience.

Results of Operations and Financial Condition On May 6, 2026, Owens Corning (the "Company") issued a press release announcing its financial results for the quarter ended March 31, 2026. Exhibit 99.1 contains certain financial measures that are considered "non-GAAP financial measures" as defined in the federal securities laws and contains an explanation and, as applicable, a reconciliation of these non-GAAP financial measures to their most directly comparable financial measures calculated and…

Executive Vice President, Chief Financial and Operating Officer — Todd W. Fister: Mr. Fister was promoted to a combined role of operational and financial leadership.

Other Events. As previously disclosed, on February 13, 2025, Owens Corning (the "Company") entered into a definitive agreement (the "Agreement") with Triumph Composites Private Limited (formerly known as Triumph Non-Ionics Pvt Ltd.) and 3B Lux S.à r.l. (together, the "Purchasers"), together with affiliated guarantors, providing for the sale of substantially all of the Company’s global glass reinforcements business (the "Transaction"). The Purchasers are affiliates of the Praana Group. The Agr…

Material Impairments. On February 14, 2025, Owens Corning (the “Company”) disclosed an expected impairment charge associated with the announced sale of the Company’s global glass reinforcements business (the “GR Business”) and that, beginning with the Quarterly Report on Form 10-Q for the period ended March 31, 2025, the GR Business’s financial results would be reflected in the Company’s consolidated financial statements as discontinued operations for all periods presented, and the GR Busines…

Results of Operations and Financial Condition On February 25, 2026, Owens Corning (the "Company") issued a press release announcing its financial results for the fourth quarter of 2025 and the fiscal year ended December 31, 2025. Exhibit 99.1 contains certain financial measures that are considered "non-GAAP financial measures" as defined in the federal securities laws and contains an explanation and, as applicable, a reconciliation of these non-GAAP financial measures to their most directly c…

Director — Maryann T. Mannen: Ms. Mannen will not stand for re-election at the Company's 2026 Annual Meeting of Stockholders.

Results of Operations and Financial Condition On November 5, 2025, Owens Corning issued a press release announcing its financial results for the quarter ended September 30, 2025. Exhibit 99.1 contains certain financial measures that are considered “non-GAAP financial measures” as defined in the federal securities laws and contains an explanation and, as applicable, a reconciliation of these non-GAAP financial measures to their most directly comparable financial measures calculated and present…

Results of Operations and Financial Condition On August 6, 2025, Owens Corning issued a press release announcing its financial results for the quarter ended June 30, 2025. Exhibit 99.1 contains certain financial measures that are considered “non-GAAP financial measures” as defined in the federal securities laws and contains an explanation and, as applicable, a reconciliation of these non-GAAP financial measures to their most directly comparable financial measures calculated and presented in a…

President, Roofing — Gunner Smith: The President of a major business segment is resigning to pursue another opportunity, representing a genuine executive departure.

Results of Operations and Financial Condition On May 7, 2025, Owens Corning issued a press release announcing its financial results for the quarter ended March 31, 2025. Exhibit 99.1 contains certain financial measures that are considered “non-GAAP financial measures” as defined in the federal securities laws and contains an explanation and, as applicable, a reconciliation of these non-GAAP financial measures to their most directly comparable financial measures calculated and presented in acc…

Material Impairments. On April 25, 2025, the Company determined that the estimated pre-tax noncash impairment charge related to the sale of the GR Business is expected to be approximately $360 million, which will be reflected in its consolidated financial statements for the quarter ended March 31, 2025 and will be reported in the Company’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2025. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, as amen…

Termination of a Material Definitive Agreement. On March 31, 2025, Owens Corning (the “Company”) terminated its existing trade receivables securitization program evidenced by that certain Third Amended and Restated Receivables Purchase Agreement, dated as of March 1, 2024, by and among certain subsidiaries of the Company, various financial institutions party thereto and PNC Bank, National Association, as administrator. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of…

Entry into a Material Definitive Agreement. On March 5, 2025, Owens Corning (the “Company”), as borrower, entered into that certain First Amendment to Second Amended and Restated Credit Agreement (the “First Amendment”) with various financial institutions, as lenders (the “Lenders”), and Wells Fargo Bank, National Association, as administrative agent (the “Agent”). The First Amendment amends that certain Second Amended and Restated Credit Agreement, dated as of March 1, 2024, among the Compan…

Commercial Paper Program On March 5, 2025, the Company established a commercial paper program (the “Program”), pursuant to which the Company may issue, on a private placement basis, unsecured commercial paper notes (the “Notes”) up to a maximum aggregate amount outstanding at any time of $1,500.0 million. Under the Program, the Company may issue the Notes from time to time. The proceeds from the Notes will be used to finance the Company’s short-term liquidity needs and other general corporate…

Results of Operations and Financial Condition On February 24, 2025, Owens Corning (the "Company") issued a press release announcing its financial results for the fourth quarter of 2024 and the fiscal year ended December 31, 2024. Exhibit 99.1 contains certain financial measures that are considered "non-GAAP financial measures" as defined in the federal securities laws and contains an explanation and, as applicable, a reconciliation of these non-GAAP financial measures to their most directly c…

Material Impairments. In connection with the Transaction (as described below), Owens Corning (the “Company”) will sell the Company’s global glass reinforcements business (the “GR Business”), which comprises part of the Company’s Composites business segment. As a result, under United States generally accepted accounting principles, beginning with the quarterly report on Form 10-Q for the period ending March 31, 2025, the GR Business’s financial results will be reflected in the Company’s consol…

President, Composites — Marcio A. Sandri: The individual is ceasing to be an executive officer of the company, which constitutes a departure from the senior management team, though they remain in a non-executive role.

Other Events. On February 13, 2025, the Company entered into a definitive agreement with Triumph Non-Ionics Pvt Ltd., a private limited company incorporated in the Republic of India (“Triumph”), and 3B Lux S.à.r.l, a private limited liability company incorporated under the Laws of the Grand Duchy of Luxembourg (“3B”) (Triumph and 3B, the “Purchasers”), Ayana Chemicals Singapore Pte. Ltd., a private limited company incorporated under the Laws of Singapore, as guarantor (“Ayana”), and Artek US…

Director — Michelle T. Collins: The filing discloses the routine addition of a new independent director and the planned non-re-election of a sitting director, which are standard board composition changes rather than executive departures.

Results of Operations and Financial Condition On November 6, 2024, Owens Corning issued a press release announcing its financial results for the quarter ended September 30, 2024. Exhibit 99.1 contains certain financial measures that are considered “non-GAAP financial measures” as defined in the federal securities laws and contains an explanation and, as applicable, a reconciliation of these non-GAAP financial measures to their most directly comparable financial measures calculated and present…

Results of Operations and Financial Condition On August 6, 2024, Owens Corning issued a press release announcing its financial results for the quarter ended June 30, 2024. Exhibit 99.1 contains certain financial measures that are considered “non-GAAP financial measures” as defined in the federal securities laws and contains an explanation and, as applicable, a reconciliation of these non-GAAP financial measures to their most directly comparable financial measures calculated and presented in a…

Other Events. In connection with the sale of $500,000,000 aggregate principal amount of 5.500% senior notes due 2027, $800,000,000 aggregate principal amount of 5.700% senior notes due 2034 and $700,000,000 aggregate principal amount of 5.950% senior notes due 2054 by Owens Corning (the “Company”), the Company is filing herewith the following exhibits to its Registration Statement on Form S-3 (File No. 333-279742): 1. Underwriting Agreement, dated as of May 29, 2024, by and among the Company…

Entry Into a Material Definitive Agreement. Exchange Offer As previously announced, on May 14, 2024, Owens Corning, a Delaware corporation (“Owens Corning”), issued a press release announcing the early results of its previously announced offer to exchange (the “Exchange Offer”) any and all 3.50% Senior Notes due 2030 (the “Existing Masonite Notes”) issued by Masonite International Corporation, a British Columbia corporation (“Masonite”), and held by certain eligible holders for up to an equal…