Plus energy house "Heliotrope

79100 Freiburg: the house turns to the sun and produces more solar energy than it consumes on average over the year. The house of the architect Rolf Disch, a pioneer of solar architecture, is probably one of the first and best-known plus-energy houses in the world. The Heliotrope is one of the few residential buildings in Europe to have a building-integrated biaxial tracking PV system. Completion: 1994

Photo gallery 2004

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Photo gallery 1996

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Sustainability measures
Ecology	PlusEnergy house: the photovoltaic system on the roof generates more electrical energy than the building consumes. Optimal use of solar energy due to the possibility of orienting the building in the optimal direction. It turned out that the re-turning requires only a little electricity (comparable to a video recorder in stand-by), but it does not lead to any major solar gains. However, the turning mechanism is very suitable for achieving summer thermal protection.use of rainwater, use of a dry composting toilet and clarification of wastewater in a reed bed sewage treatment plant.
Economics	The rotating mechanism for the building was cheaper than a shading system. Parts of the development and construction of the building were funded by the Ministry of Economic Affairs and Technology of the State of Baden-Württemberg.
Socio-cultural	The Heliotrope is used as an image carrier for ecological building, as it arouses great public interest due to its innovative form.
Special features	The Heliotrope is one of only a few houses that has a dual-axis tracking PV system. With an optimally designed system, this results in an annual average of up to 45% additional yield compared to a system mounted permanently facing south.
Awards	Special prize at the competition "The Golden House" 1996 Special prize at the competition "Freiburger Innovationspreis" 1996 German Architecture Award 1995 Recognition