Buildings are bad news for the climate -- but they don't have to be. While our structures are currently responsible for a third of global energy consumption and emissions, a future where they create more energy than they consume is possible. This week we are revisiting a talk by energy policy analyst Ksenia Petrichenko who has a three-tiered strategy for thinking differently about buildings, transforming them from passive users to active players in the energy system and bringing us closer to our climate targets.