X0306 4 2021-08-06 0 0001370946 Owens Corning OC 0001385266 MORRIS W HOWARD ONE OWENS CORNING PARKWAY TOLEDO OH 43659 1 0 0 0 $.01 Par Value Common 2021-08-06 4 A 0 91.625 0.00 A 39867.118 D $.01 Par Value Common 2021-08-09 4 S 0 1904 95.60 D 37963.118 D Additional shares reflect the reinvestment of dividends or dividend equivalents. The price reported is a weighted average sale price. These shares were sold in multiple transactions at prices ranging from $95.58 - $95.62, inclusive. The Reporting Person undertakes to provide to Owens Corning, any security holder of Owens Corning, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. /s/Omar N. Chaudhary, Attorney-in-Fact 2021-08-10