“The apartment building, hosting 48 flats, was built in 1970 as a modest, practically non-insulated, concrete structure. A change in the apartment sizes was therefore impossible for cost reasons. Consequently the structure has been maintained with small apartments, even though it was possible to add a top storey with larger apartments. The house now comprises 50 apartments with 1 to 3 rooms.
About 60 people live in the house with a total space requirement of only 35 m² per person. The demand for hot water is correspondingly high. The large closed facade areas and the removal of an exhaust air duct of the underground car park led to a new energy concept: 180 m² of thermal solar collectors integrated in the facades and a 19 meter high water storage tank in the former exhaust duct. A heat pump with four geothermal probes and 150 m² photovoltaic on the roof complete the energy system. The energy colander of the past is now fully equipped for the demands of our times.
The vertical solar collectors stretch the building upwards and are covered with a glass that changes its appearance from bronze to silver (Kromatix). In addition, hop plants are a guarding part of the facades, making a contribution to urban ecology.”
View of the building before the retrofit
Interior view of the top storey.
|Active solar surface||230m²||181m²|
|Active solar surface ratio||<75%||>25%|
|Peak power||36 kWp||N.A.|
|Building skin application||Added installation||Cold facade|
|Storage||Water tank, storage battery||19000 lt, 20kWh|
The existing windows have been all replaced.
“DOMA FLEX large-area solar thermal collectors are located on three facades; 36m2 are located on the East and West Facades and 108m2 on the southern facade. Because of the different locations of the solar collectors, energy is produced throughout the entire day. Although the vertical instillation of the solar collectors reduces the yield in the summer, it optimizes in the warmth production in the winter. The glass for the solar collectors are custom-made by Doma-Schweizer in Vorarlberg (Austria). They are coated with a Kromatix glass from Swissinso. The color of the collector changes from grey to bronze, with the angle of view and the intensity of the sun.”