According to the U.S. Green Building Council, buildings are responsible for 40% of the country’s energy consumption, and 39% of the CO2 emissions. Therefore, buildings represent an important target for greenhouse gas reduction, and during the last decade the country has seen significant progress in that regard, from the USGBC’s Leadership in Energy and Environmental Design certification system, to the Architecture 2030 Challenge, to CALGreen, the first mandatory statewide green building code in the nation. The ultimate goal is zero energy buildings – structures that make as much energy as they consume. The hosts discuss innovations in energy-efficient buildings and greenhouse gas reduction with Roger Frechette, President of PositivEnergy Practice, whose work focuses on sustainable engineering and building design.