Passive House is a voluntary international building standard developed by the Passive House Institute (PHI), located in Darmstadt, Germany. The Passive House Standard is composed of several strict performance requirements for new building construction. For the renovation of existing buildings, PHI developed a similar, slightly more lenient performance standard. The resulting performance produces approximately a 90% reduction in heating and cooling energy usage and up to a 75% reduction in primary energy usage compared to homes built to conventional building code. Passive House significantly reduces the carbon footprint of a home while making a comfortable, healthy, and affordable environment.