The Gemini house is a prototype design for a house that uses solar energy and efficient design. Roland Mösl created the concept in Autumn 1991. The name expresses a design goal: that the real estate on which the house stands will be used simultaneously for two purposes. It should not be possible to built a better house on the same ground, and it should not be possible to built a better solar power plant either. In 1992 - 1993 Roland Mösl wrote a book, in German, about the project: Aufstieg zum Solarzeitalter (Advance to the solar age) and made efforts to find an investor. The plans were an expression of the most extreme solar architecture. A cylindric house would turn to follow the sun, and be equipped with up to 150m² of photovoltaic panels. Extreme thermal insulation, and heat recovery from waste air were also included. The project won a prize at the 1993 EUREKA world innovation fair in Brussels. But it took several years more to create a prototype. In 2001 there was a national exhibition about energy in Styria, Austria. Because of this, the Gemini project was able to gain the funds to build the prototype as the main attraction of this exhibition. The prototype was built in Weiz, a small town north of Graz in Austria. It was the first energy plus house (self-sufficient, and sometimes more) in Austria.
