http://en.wikipedia.org/wiki/Passive_house

Passivhaus in German) refers to the rigorous, voluntary, Passivhaus standard for energy use in buildings. It results in ultra-low energy buildings that require little energy for space heating.[1] A similar standard, MINERGIE-P®, is used in Switzerland [2]. Despite the name, the standard is not confined only to houses. Several office buildings, schools, kindergartens and a supermarket have also been constructed to the standard. Passive design is not the attachment or supplement of architectural design, but an integrated design process with the architectural design.[3] Although it is mostly applied to new buildings, it has also been used for refurbishments.