2021 Owens Corning Sustainability Report | Expanding Our Product Handprint | Supply Chain Sustainability | 126 Acquisitions and Supply Chain Sustainability Bolt-on acquisitions are part of Owens Corning’s strategy for growth. With acquisitions come new suppliers, many of which are significant and many of which are based outside the U.S. Whenever we consider acquiring another company, we exercise due diligence to evaluate supply chain risk. It is important that the target company’s current suppliers are high-quality, capable, safe, and able to meet our standards. Soon after a transaction is completed, we engage with each acquired business to set expectations and implement a consistent structure for supplier relationships. We provide extensive training to ensure that the acquired business understands our Supplier Code of Conduct and how to administer it. In addition, our commodity leaders spend time getting to know the acquired company’s key suppliers, explaining the Supplier Code of Conduct, following up on issues of concern, and, if necessary, identifying alternative potential suppliers. In 2021, Owens Corning acquired vliepa GmbH, a German-based company specializing in the coating, printing, and finishing of nonwovens, paper, and film for the building materials industry. While the company is undergoing the processes associated with acquisition, their data does not factor into this year’s overall supply chain performance figures. In 2021, Owens Corning enhanced our approach to prioritizing suppliers, empowering us to further emphasize the importance of sustainability throughout our value chain. This approach provides additional consideration of our suppliers’ environmental, social, and governance (ESG) risk exposures. The environmental, social, and governance risk scoring framework is based on S&P Global Rating’s ESG Risk Atlas. A sector risk score, which encompasses associated environmental and social risk rationales, is assigned based on the commodity a supplier supplies to Owens Corning. A regional risk score, which embodies governance rationales, is assigned to a supplier’s country. The overall ESG Risk Score is then tallied for each supplier by adding the three E, S, and G risk scores. For suppliers who provide multiple commodities to Owens Corning, and therefore have potentially multiple ESG risk scores, we selected the highest ESG risk score to conservatively represent these suppliers. PRIORITIZING SUPPLIERS USING ESG RISK SCORING Photo submitted by: Kelly Picking | Toledo, Ohio, U.S.

Owens Corning Sustainability Report - Page 126 Owens Corning Sustainability Report Page 125 Page 127