Using the concept of the solar-powered PlusEnergy living unit helps illustrate the potential for creating additional high-quality living space within existing buildings. Roof/attic spaces that have thus far remained unused are replaced by a one- or two-storey lightweight wooden construction, the roof of which is almost completely covered with photovoltaic modules.
The PV generator produces more electrical energy (yearly average) than the Rooftop apartment requires to function. This provides excess energy which can be used in the living units in the pre-existing building below it..
Two variations of the Rooftop Building (one- and two-storey) can be explored on the roof of a Gründerzeit building in Berlin in a virtual model of an urban district.