Passive Houses are built according to a rigorous series of design principles that promote efficiency.
The basic building block of a certified Passive House is a virtually airtight, superinsulated envelope that prevents the infiltration of outside air and the loss of conditioned air. Because joints and cracks aren’t a sufficient source of fresh air, Passive Houses are equipped with a ventilator that takes heat from the stale exhaust air and transfers it to the air that is being drawn in from the outside. (In summer, the process reverses, with the cool inside air pretreating the hot intake air before being vented outside.) Passive Houses also are positioned to capture the sun’s natural heating capabilities in the winter while minimizing solar gain in the summer.