Passive house

Passive house (Passivhaus) is a voluntary standard for energy efficiency in a building, which reduces the building's ecological footprint. It results in ultra-low energy buildings that require little energy for space heating or cooling. A similar standard, MINERGIE-P, is used in Switzerland. The standard is not confined to residential properties; several office buildings, schools, kindergartens and a supermarket have also been constructed to the standard. The design is not an attachment or supplement to architectural design, but a design process that integrates with architectural design. Although it is generally applied to new buildings, it has also been used for refurbishments. In 2008, estimates of the number of passive house buildings around the world ranged from 15,000 to 20,000 structures. In 2016, there were approximately 60,000 such certified structures of all types worldwide. The vast majority of passive structures have been built in German-speaking countries and Scandinavia. The passivhaus standard originated from a conversation in May 1988 between Bo Adamson of Lund University, in Sweden, and Wolfgang Feist of the Institut für Wohnen und Umwelt (Institute for Housing and the Environment), in Darmstadt, Germany. Later, their concept was further developed through a number of research projects, aided by financial assistance from the German state of Hessen. Much of the early "passive houses" builds were based on research and the experience of North American builders during the 1970s, who – in response to the oil embargo – sought to build homes that used very little to no energy. These designs often utilized expansive solar-gain windows, which used the sun as a heat source. However, superinsulation prevailed over, as seen in the Saskatchewan Conservation House (1977) and the Leger House in Pepperell, Massachusetts (1977). The Saskatchewan Conservation house was a project of the Saskatchewan Research Council (SRC), who independently developed a heat recovery air exchanger (HRV), hot water recovery, and a blower-door apparatus to measure building air-tightness — notably the house was designed for the extreme -40C to +40C climate of the Canadian prairie.