The Kühar/Breitfuß family has opted for a sustainable overall concept with the BES system for the new apartment building and the renovation of the existing building. The system includes a 100 kW PRIME heat pump, 124 m² of thermal solar collectors and 1,672 m² of geothermal storage, and supplies the 1,452 m² of the new building and 816 m² of the existing building.