Schloss Retzhof is a hotel and conference center which had three different construction periods (16th c.,1960, 2009). The three buildings were supplied by a heating network; with a total heating area 4.000 m2.
The initial situation: inefficient natural gas boiler, high energy cost. No insulation of building envelope (protection of historic monument). Energy consumption ratio ~ 185 kWh/m2/year. Demolition of boiler house to make room for new guest house.
Goals of building owner: