European Solar Prize goes to Switzerland
The Swiss architecture firm "Bauatelier Metzler" receives the European Solar Prize for an apartment building from the 1950s that has been converted into a plus-energy building.
Following the Swiss Solar Prize 2015, now also the award from Europe: The PlusEnergy house in Oberenstringen was awarded the European Solar Prize 2015 awarded. Responsible for the reconstruction is the architecture office "Building studio Metzler„.
There are thousands of comparable buildings in Switzerland. Many are in need of renovation. The fact that a building from this period can be economically converted into a PlusEnergyBuilding (PEB) proves the enormous potential that exists in the Swiss building stock in terms of energy efficiency.
Several parameters posed a challenge for the planning team of Bauatelier Metzler during the conversion project:
- Thomas Hardegger's apartment building is located in the core zone of the municipality of Oberengstringen;
- various thermal bridges were eliminated through a completely new insulated building envelope, the removal of the old balconies and the construction of a new attractive balcony tower on the south side;
- The newly insulated roof was also fitted with a high-performance in-roof photovoltaic system on the south and north sides and on the two skylights. The north-facing PV system still has a capacity of around 60 percent of the south-facing PV system. A PV system on the south façade or on the balcony tower would have been more expensive per kW output. For this reason, the installation of a north-facing PV system was realized: Compared to the south-facing façade panel variant, the area of the roof panels is larger and much less expensive.
In addition, the house was planned and awarded the Minergie-P-ECO sustainability label. This is also a pioneering achievement in the field of multi-family house conversion.
The calculated Minergie-P limit value of the four-family house is 29.5 kWh/m2. Heat and hot water are generated by a heat pump of only 8 kW. The photovoltaic system with a total of 118 modules on the north and south roofs has a capacity of approximately 31 kwp, which results in an annual yield of approximately 25,500 kWh.
In numbers:
Total energy demand old building: 66`500 kWh/a
Total energy demand new building: 18`500 kWh/a
Self-energy supply (PV) New building: 25`500 kWh/a
Energy surplus new building: 7`000 kWh/a
