More than a dozen 'surplus energy' homes are currently available by the German prefab housing market, a trend that is increasing. Faster than many expected, a concept is thus being established on the mainstream market which, until recently, was still the domain of research institutions, universities and a few pioneering architects and engineers. The pace has been set by the German Federal Ministry of Building, Transportation and Urban Development, which at the end of 2011 completed its own 'Efficient Home Plus Electro-mobility' designed by Werner Sobek and his team (Ill. 3).
