Buildings are a significant source of greenhouse gas (GHG) emissions. Much has been done to lower operational carbon. However, GHG emissions from construction activities and embodied in the materials used to build buildings can, in certain circumstances, constitute a majority of the 10-15-year GHG footprint of a building. Decarbonization of construction materials is a viable and scalable opportunity for project teams and can contribute to achievement of LEED certification. This webinar will cover basics of GHG accounting and foot printing of construction materials, and introduce the EC3 tool as a viable means for owners, designers and contractors to reduce GHG emissions in their building projects.