The Erni family’s detached house in Thun, built in 1953 in the style of a chalet, was renovated in 2020, preserving the original structure of the building. Its energy performance was improved in order to obtain Swiss Plus-Energy building certification. Thanks to the improvement in energy efficiency of the building envelope and the use of energy-saving appliances, the total energy requirements of the building have been reduced by 85%, from 48,500 kWh/year to 7,500 kWh/year. Both sections of the roof are covered with integrated photovoltaic modules.

Sources: Schweizer Solarpreis 2021