Built in the 1970s, the properties are in need of refurbishment and do not meet today's aesthetic requirements or current standards for fire protection and load-bearing capacity. For this reason, a comprehensive complete refurbishment is being carried out in an unoccupied state. Kitchens, bathrooms and all building services and electrical installations will be replaced. The oil heating systems will be replaced by geothermal probe heat pumps, and the building envelope will be optimised in terms of energy efficiency by means of thermal insulation on the façade and roof. Photovoltaic systems will be installed on the flat roofs, which will cover a large part of the electricity requirements in future. The refurbishment comprises 14 apartment blocks, the car park and outdoor areas and is being carried out in three construction phases.