Heat Pumps in Apartment Buildings

Wärmepumpen in Mehrfamilienhäusern
© Fraunhofer ISE

The building sector is responsible for around 40 percent of CO2 emissions in Germany. To reduce emissions in this sector more significantly than before, heat pumps are playing an increasingly important role in apartment buildings. However, the requirements for the design of the heat pump and the overall system are more complex in multi-family houses than in single-family houses. In addition to questions of hot water preparation and the heat transfer system, the use of environmental energy at the location (heat source) must be included in the considerations. In residential buildings, geothermal energy or outside air is usually used as a heat source; if available, waste heat from waste water is an interesting option. Photovoltaic-thermal collectors (PVT), which are installed on house roofs and simultaneously serve as a source of heat and electricity for heat pumps, can be a real alternative, especially in urban areas where space is at a premium.


  • heat pumps in apartment buildings are more profitable in the long term than gas heating systems
  • long-term climate neutrality for a very large building sector
  • couples well with photovoltaics, solar thermal energy and heating networks
  • high share of renewable energy possible by using local ambient heat

R&D on Heat Pumps in Apartment Buildings:

  • integration of hot water provision into the overall concept to ensure sufficiently high temperatures
  • investigation and optimization of extraction systems for environmental heat (outside air, geothermal energy, ground water, waste water, solar thermal energy)
  • market analysis and determination of economic effects
  • potential analyses for grid-supportive operation

Our R&D Services on this Topic:

Project Network “LowEx-Bestand”

Annex 62

Heat Pumps in Multi-Family Buildings

Case Studies examples in Europe.

Research Project


Development of Heat Pump Solutions with Propane for the Replacement of Gas and Oil Appliances