Shaping the heat transition – innovation in series production Strategic partnership between Vonovia, EnerCube and DFA Demonstrationsfabrik Aachen enters new phase – first heat pump cubes delivered to neighbourhood in North Rhine-Westphalia

Aachen, 13 March 2026 – As the first heat pump cubes emerge from the production line and are installed in an Aachen neighbourhood, the strategic partnership between Vonovia SE, EnerCube GmbH and DFA Demonstrationsfabrik Aachen GmbH continues to take shape.

In 2025, the three partners concluded a cooperation agreement on the mass production of their innovative heat pump system for apartment buildings. Under the motto “Shaping the heat transition – innovation in series production”, over 1,000 cubes will be built in Aachen by the end of 2029 and will then be installed in Vonovia neighbourhoods throughout Germany. They will provide heating for more than 20,000 further homes, without the use of gas or oil.

The serial use of heat pump cubes marks a significant step forward in the shift to renewable energies in existing buildings, and the partnership is moving ahead smoothly towards its objective. By the end of 2026, a nationwide total of 100 cubes will be installed throughout Germany, making a substantial contribution to a climate-friendly heat supply. In 2025, the number of cubes had already reached 40.

“The shift to renewable energies can only succeed with the help of innovations. Our heat pump cubes are systems that can be installed quickly and easily in existing buildings.  A climate-neutral supply of heating and hot water serves both our customers and the protection of our climate. By working together with our capable partners, we are gaining even more momentum on our road to climate neutrality now,” says Arnd Fittkau, member of the Vonovia Management Board.

The heat pump cube is a compact heating system developed by the Austrian start-up company EnerCube. Each compact cube houses not only a heat pump but also all the key components of the heating system. It is then installed within a residential environment, but outside the actual buildings. This modular solution will replace conventional heating systems at locations without connections to local or district heating networks. The switch to a direct, sustainable supply also has a positive impact on operating costs. The concept is now being developed for industry-scale production by the Aachen-based company Demonstrationsfabrik Aachen GmbH (DFA).

The cubes are available in several power ratings, and one cube typically supplies 10 to 60 homes with sustainable heat from the ambient air. Thanks to its built-in sound insulation, the system is suitable even for high-density housing estates. The high degree of prefabrication significantly reduces on-site set-up times, so that installation can be undertaken regardless of cramped boiler rooms or limited access to a building. Maintenance and repairs can be carried out on this external system without any disruption to residents.

“Our joint preparations and production launch have confirmed what we had expected, showing that great things can be achieved when the right people or partners work together and each contributes their own strengths. We can therefore be positive about the future and the huge challenge of the shift to renewable energies,” says Laurenz Sutterlüty, founder and CEO of EnerCube GmbH.

“We've spent the last few months working hard to optimise the product for mass production, so that the CUBE is now in its third generation We really appreciate our partner's professionalism, thoroughness and manufacturing experience, which has resulted in a close and trusting working relationship,” adds David Riedl, founder and CEO of EnerCube GmbH.

“The first cubes to leave our production line were more than just a milestone for us – they were the starting signal. This is where genuine industry-scale production begins: the hardest and most decisive step as we proceed from innovation to successful realisation. Together with Vonovia and EnerCube, we are pushing ahead with this ramp-up, so that our shift to renewable heating in existing buildings will be more than a vision. It will be reality,” says Prof. Wolfgang Boos, CEO of DFA Demonstrationsfabrik Aachen GmbH.