First things first: What's a Passive House? They're well insulated, virtually airtight buildings who must meet strict energy efficiency requirements. The benefit is that building passive can decrease home heating consumption by an astounding 90% and decrease overall energy consumption up to 75%. Here, a mixed-use building in Williamsburg, Brooklyn, with a single-family home atop a retail space, all designed by Loadingdock5. Photo by: Raimund Koch.