Project details



HeAt PumPs in existing multi-family buildings for achieving union's ENergy and envIromeNtal Goals

Start date: 01.10.2020

Duration: 42 months

Coordinator: TECNALIA

Budget: 2.5 M€


Currently, buildings are responsible for 40% of the energy demand and 36% of the CO2 emissions in Europe. Decarbonisation of existing buildings plays a key role in order to reach the overall climate protection targets. However, current renovation rates lie in the order of 1%.​

Heat pumps are a key technology in bringing renewable shares into heat supply of buildings; especially their combination with onsite renewable electricity production e.g. by PV allows to bring high renewable shares. Their current installation in existing multi-apartment buildings is however still marginal.​

The proposed technological solution is based on decentralized heat pumps, in such a way that it results an easyto-install solution for installers, low-intrusive for the occupants and easily adaptable to a large number of different building situations. This is flanked by developing near-zero planning, implementation and operation processes, in order to facilitate the work during the planning phase, ensure a high-quality installation and effective operation, and reduce the efforts and costs within the whole retrofitting project. The challenge of cost-competitiveness is addressed by developing new financial and business models. Bringing new players (such as financial experts) and financing models to the renovation market is expected to bring the needed paradigm change and boost investments in the residential retrofitting sector. Dissemination of measured performance and system characteristics from HAPPENING will be one of the key results of the project.​

List of achievements

Through 3 demo sites (Spain, Italy and Austria), the project will demonstrate a highly versatile, scalable and replicable solution package for buildings energy system retrofitting allowing 70-75% of renewable energy fraction, 30-50% of PE and GHG savings, reduction of planning time by 50% and installation/operation time by 30% and payback time for ESCOs and investors of less than 8 years, compared to best available solution existing today.

More information about the Pilot sites here.


Contact person: Irantzu Urkola


In progress