In autumn 2021, four settlement communities applied to participate in the W4RES project together with the regional association “Verband Haus- und Wohneigentum”.
The “Verband Haus- und Wohneigentum e.V.” (VHWE) is the biggest organisation of all family home owners in Germany. Its mission is to provide access to self-occupied housing for citizens who earn average or below average income.
During the project HFT Stuttgart has analysed, together with the participating communities and head-office, the topics of photovoltaics, energetic renovation and renewable heat supply.
In the case of photovoltaics, it is important to figure out how much electricity can be generated on one’s own building. From the 1st of January 2023, a solar obligation will apply for new buildings and, in case of significant roof conversions, also to existing buildings in Berlin. Then, 30% of the roof area will need to be covered with photovoltaic systems.
For the project, the HFT team has used special tools for analysing three-dimensional building models of the residential communities, which are provided free of charge by the state of Berlin. The team has compared two options. In the first option, only the fulfilment of the solar obligation is assumed in the case of roof conversion. In the second case, it is assumed that all available and reasonably usable roof surfaces are occupied by photovoltaic system. The calculations are discussed with representatives from the communities and compared with the actual conditions on site.
For energy retrofits HFT has created a comparison of three retrofit options based on the three-dimensional building model and years of construction to show how much energy can be saved if certain measures, such as insulating the roof, are implemented. To get more accurate results, further information is needed from the participating communities on actual energy consumption and measures already implemented. Therefore the four communities have launched a survey among members: this information has helped for a more detailed analysis and forms the basis for future projects.
Further projects planned
As a regional association we see the energy transition and the participation of all settlement families in the energy transition as a major challenge. Therefore we are permanently in discussion with potential project partners and politicians and looking for support in other projects. For example, there is an ongoing application to assist communities with climate adaptation. We will use the information gained in W4RES as a basis for further projects – in consultation with the communities.