2021 Owens Corning Sustainability Report | Reducing Our Environmental Footprint | Combating Climate Change | 156 Business Travel Rental car mileage and commercial air travel miles and emissions were received from our travel vendor. For employee vehicle reimbursement related to business mileage, Owens Corning used an extract of miles from our travel system and determined emissions based on a standard emission rate provided by the U.S. EPA Greenhouse Gas Emissions from a Typical Passenger Vehicle guide. Employee Commuting Owens Corning used a simplified version of the Scope 3 GHG Protocol’s average- data method to calculate employee commuting emissions. We used the U.S. EPA’s guide to determine an estimate of grams of CO 2 per mile, and we used the average number of days worked per year to estimate employee commuting. We believe this estimate is overstated because our calculations did not take into account telecommuting, public transportation, carpooling, business travel days that would be accounted for separately, or other methods of commuting. Processing of Sold Products Many of our products, including asphalt roofing shingles and insulation products, do not require additional processing or energy sources to perform their function. Additional downstream processing, however, is common with intermediate products — reinforcement glass fiber, for example, is often used in reinforced plastic composites. To determine the GHG emissions from this category, we correlate the revenue generated from our Composites business to the GHG emissions of industry sectors that represent our glass-fiber reinforced plastic (GFRP) customers. We calculate Scope 3 emissions for these products using the EIO-LCA online tool. End-of-Life (EoL) Treatment of Sold Products While we have continued to develop innovative options for recycling asphalt roofing shingles and GFRP materials, insulation products are more likely to be sent to landfill. Scope 3 EoL emissions were determined for Owens Corning insulation manufacturing operations related to fiberglass and XPS insulation. We determine the impact of this category by calculating the GHG emissions generated when all the glass wool and XPS foam produced by our North American facilities for 2021 is sent to landfill. EoL emission factors were determined from cradle-to-grave EPDs, and the LCAs upon which they are based, on Owens Corning fiberglass insulation and XPS insulation. The third-party verified LCAs were internally conducted for these products in 2017 and 2018, respectively. These factors were used in conjunction with 2021 production volumes for these two insulation materials to determine the Scope 3 emissions when the production volume quantities are disposed as waste to landfill. Customers About 40% of GHG emissions in the world today come from buildings, so they are an essential target for reducing emissions. Given that the building and construction industry represents one of our main markets, we qualitatively and quantitatively monitor the GHG emissions from buildings in relation to their energy efficiency. Our commitment to sustainability includes energy-saving products such as insulation and air-sealing products. We estimate that the insulation we produced in North American in 2021 reduced GHG emissions for homeowners by approximately 10.5 million metric tons a year and 632 million metric tons over a 60-year building life. According to the trade association NAIMA, a typical unit of fiberglass insulation saves 12 times as much energy in its first year of use as the energy used to produce it. That means the energy consumed during manufacturing is saved during the first four to five weeks of product use. Our glass fiber composites contribute to light-weighting of vehicles for better fuel efficiency, better efficiency of wind turbines, and lower embodied energy than competing materials over the life of the part. We collaborate with customers to conduct LCAs for their products as well. Further details on renewable energy and other emissions reduction initiatives, including green buildings and energy-efficient products, can be found in our Energy Efficiency & Sourcing Renewable Energy chapter . For detailed examples of our 2021 emission reduction projects, please see Owens Corning’s CDP Climate Change 2022 Report, which will be published later this year.