Aktiv-Stadthaus, Frankfurt

There is only one topic here: Energy!

Aktiv-Stadthaus Frankfurt: the building that is an energy supplier

Plus-energy houses have mostly been built as individual houses up to now. The Aktiv-Stadthaus in Frankfurt, probably one of the largest plus-energy houses in Europe, shows that positive energy balances are also achievable in multi-storey residential buildings. The concept: a highly efficient photovoltaic system on the roof and façades generates electricity which is stored in batteries in the basement of the building. A heat pump also makes heat from the waste water channel usable for heating and hot water. In this way the building generates all the energy required by the occupants itself.

The effectiveness of this innovative concept will be studied intensively over the next few years. Therefore development partners are on board with the monitoring and evaluation of results – the Steinbeis-Transfer Centre for Energy, Buildings and Solar Technology as well as the Technical University of Darmstadt.

For this purpose the usage patterns of the occupants are also observed. Individual energy consumption is visible on a display in each apartment and the amount of energy the building is currently producing can also be seen. The target is to match supply with demand. The consumer should not be limited by these measures – rather, the assumption is that the information will encourage a more conscious consumption of energy.

"Solar construction with its current possibilities does not limit architecture; it sets new challenges – and new levels of freedom", said German Federal Minister Barbara Hendricks at the opening of the Frankfurt Aktiv-Stadthaus. The Aktiv-Stadthaus demonstrates that these challenges can be met.

Year of construction: 2015
Builder: ABG Holding (city-owned Frankfurt Residential Housing Association)
Number of apartments: 75
Heated net floor area: 6,480 m2
Heated building volume: 31,217 m3
Energy surplus: 43,622 kWh/a*
* this corresponds to the annual mileage of a medium electric car
of approx. 256,600 km (17 kWh/100km)
Eco values:
External walls: 0.13 W/(m2K) (averaged)
Roof above 7th floor: 0.09 W/(m2K)
Windows with triple glazing: 0.72 – 0.80 W/(m2K)