Submitted by: Müller Bau GmbH & Co
Implemented country: Austria
Title: Renovation of an old home to save energy
A house built in Vorarlberg, Austria, was renovated in 1968 to save energy. The oil heating was replaced by a heat pump with a deep geothermal bore. A thermally insulating façade that extends down to the cellar was installed along with triple-glazed aluminum/wood windows. An addition on the west side enabled two additional apartments with 125-130 m² each; these were equipped with heat recovery automatic ventilation. The upper apartment uses a modern bus system that controls the complete lighting and the wind protection for the shades. The goal was to rid the property of fossil fuels and to reduce the energy demand. The renovation reduced the annual energy requirement from 150 kWh/m²a to 42 kWh/m²a; thus despite the addition, the total building now requires less than one third of the energy, saving some €1500 annually.