Nausassiche Heimstadt claims to have build the very first plus energy-apartment building in Germany in Frankfurt Riedberg, a large new housing area on the northern outskirts of the city.
Both the tilted roof and the closed parts of the south façade are completely covered in Photovoltaic cells which provide the single energy source of the full electric building. The building, which has a peculiar shape, due to the site, contains 17 apartments in different sizes.
The nicest part of the building is the light and spatial central staircase. German fire regulations did not require a second or closed staircase, therefor the architects could make an open staircase with light from above.