Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☑ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-33100 Owens Corning (Exact name of registrant as specified in its charter) (State or other jurisdiction of inco ...

Financial Data and Key Metrics Changes - In Q4 2020, the company reported revenue of $1.9 billion, a 14% increase compared to Q4 2019, and adjusted EBIT of $306 million, up 50% from the same period last year [16][31] - For the full year 2020, revenues were $7.1 billion, down 1%, while adjusted EBIT was $878 million, a 6% improvement over 2019 [17][33] - The company achieved record operating and free cash flow of $1.1 billion and $828 million, respectively, during the year [25][55] Business Line Data and Key Metrics Changes - Insulation sales for Q4 were $728 million, up 1% from Q4 2019, with EBIT of $106 million, an increase of $17 million compared to the previous year [39][42] - Composites sales for Q4 were $547 million, up 14%, with EBIT of $60 million, a $4 million increase from the same period last year [45][46] - Roofing sales for Q4 were $702 million, a 33% increase compared to Q4 2019, with EBIT of $183 million, up $96 million from the prior year [49][51] Market Data and Key Metrics Changes - The U.S. residential market, which impacts all three business segments, saw strong demand driven by increased repair and remodeling activity and higher new construction starts [18][19] - The market demand for shingles grew by 10% versus 2019, driven by above-average storm demand and a strong second half remodeling market [21] Company Strategy and Development Direction - The company is focused on capitalizing on near-term market opportunities and longer-term secular trends, including increased demand for new housing and remodeling investments [71][72] - Sustainability is central to the company's purpose, with ongoing investments in achieving 2030 sustainability goals [26][29] Management's Comments on Operating Environment and Future Outlook - Management expressed optimism about the strength in residential markets and improving conditions in commercial and industrial markets for 2021 [62] - The company expects significant revenue and adjusted EBIT growth in Q1 2021 compared to the prior year [63] Other Important Information - The company returned approximately $400 million to shareholders through share repurchases and dividends during the year [25][55] - The Board of Directors declared a quarterly cash dividend of $0.26 per share, reflecting a commitment to strong cash flow generation [58] Q&A Session Summary Question: Insulation business capacity and growth potential - Management indicated that the Kansas City facility will help meet increased demand and potentially outpace broader market growth, with an average production line representing about 3% of industry capacity [81] Question: North America pricing and realization - Management confirmed positive price realization in Q4, driven by residential demand, and indicated that an April price increase is expected to help manage inflationary pressures [88] Question: Roofing inventory levels and demand - Management noted that roofing inventory levels finished Q4 at historically low levels, with expectations to continue shipping at full capacity in Q1 [91] Question: Composites segment performance and demand drivers - Management highlighted broad-based demand drivers in Q4, including strong performance in wind energy and automotive sectors, and expects continued strong demand in Q1 [95] Question: Impact of automotive production curtailments - Management acknowledged potential impacts from automotive production curtailments but expects overall automotive demand to ramp up throughout the year [99] Question: Roofing cost inflation and asphalt pricing - Management indicated that asphalt costs have been increasing and expects to transition into an inflationary environment in Q2, with ongoing monitoring of oil prices and refinery utilization rates [102] Question: Roofing margin expectations - Management reiterated that long-term roofing margins are expected to be around 20%, with potential fluctuations based on market conditions and inflationary pressures [104]

Brian Chambers | Chairman & Chief Executive Officer Ken Parks | Chief Financial Officer February 17, 2021 | Q4 & FY 2020 FOURTH-QUARTER AND FULL-YEAR 2020 RESULTS FORWARD-LOOKING STATEMENTS AND NON-GAAP MEASURES This presentation and the associated remarks contain forward-looking statements. We caution you against relying on these statements as they involve risks and uncertainties that are difficult to predict and the Company's actual results may differ materially from those projected. Such risks and uncert ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☑ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-33100 Owens Corning (Exact name of registrant as specified in its charter) Delaware 43-2109021 (State or other jurisdiction of incorporation or o ...

Owens Corning (NYSE:OC) Q3 2020 Earnings Conference Call October 28, 2020 9:00 AM ET Company Participants Amber Wohlfarth - Director, Investor Relations Brian Chambers - Chairman and Chief Executive Officer Ken Parks - Senior Vice President and Chief Financial Officer Conference Call Participants Matthew Bouley - Barclays Stephen Kim - Evercore ISI Truman Patterson - Wells Fargo Phil Ng - Jefferies Anthony Pettinari - Citi John Lovallo - Bank of America Susan Maklari - Goldman Sachs Michael Rehaut - JPMorga ...

Q3 2020 This presentation shared at the following events: FOCUSED ON SHAREHOLDER VALUE | --- | --- | --- | --- | |----------|-------------------------------------------------------|----------------------------------------|-------| | 09/15/20 | J.P. Morgan U.S. All Stars Conference | Scott Cripps \| VP, Investor Relations | | | 09/14/20 | RBC Capital Markets Global Industrials Conference | Scott Cripps \| VP, Investor Relations | | | 09/10/20 | OC (Virtual) Roadshow Hosted by Goldman Sachs | Marcio Sandri \| ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☑ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-33100 Owens Corning (Exact name of registrant as specified in its charter) Delaware 43-2109021 (State or ot ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☑ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-33100 Owens Corning (Exact name of registrant as specified in its charter) Delaware 43-2109021 (State or other j ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☑ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-33100 Owens Corning (Exact name of registrant as specified in its charter) Delaware 43-2109021 (State or other ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☑ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 1-33100 Owens Corning (Exact name of registrant as specified in its charter) Delaware 43-2109021 (State or other jurisdiction of incorporation or o ...