Beyond the energy used during building operations, the construction of buildings causes atmospheric emission of carbon dioxide and CO2-equivalent gases (CO2e). Some of these emissions are related to the materials’ “embodied energy” but some materials have high emissions due to other factors, such as direct emissions from chemical processes, or the use of high GWP blowing agents. We can quantify these emissions, and learn how to reduce them by design. This workshop delves into the magnitude of CO2e emissions of building structures of steel, concrete, masonry and wood, as well as facade and window construction, based on new information from Environmental Product Declarations (EPDs) and other sources. We will tally emissions represented by the construction of a standard commercial building, and explore the effect that design decisions can make on the tally. Then we will compare this to the annual emissions of heating and cooling the same building.