Old town house Bonn


The former town hall lies in the historical centre of the city and was built in the 18th century in Rocco style, but it was severely damaged during the Second World War. It was rebuilt in 1950 and retrofitted between 2009-2011. Now it hosts the mayor's office, but also occasional receptions and weddings.

What was implemeted

The building was restructured on the interior, insulated, and thermal bridges were eliminated. A 142,6 kW heat pump, provided by Ochsner, is using ground water with a temperature of 10oC as a heat source to deliver heating in the house at 35oC. The heat is delivered through floor heating, for the ground floor, and ventilation systems for the rest of the house. The heat pump also provides cooling capacities, with a power if 157,7 kW.

The house was fitted with an automation system, and 40 thermostats are spread around the building to achieve personalized temperatures and to contribute to energy savings.


                                                                                                         Photo: Ochsner

  • operating costs are 1/3 than before retrofitting
  • COemissions halved