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. A similar standard, MINERGIE-P®, is used in Switzerland . 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. Although it is mostly applied to new buildings, it has also been used for refurbishments.