Development of refurbishment concepts - The case of multi-family houses from the 1970s in Western Germany

The European housing stock is dominated by properties built before the 1980s. These buildings are to a great extent far behind current technical and social requirements. This paper develops a supply- and demand-oriented refurbishment concept for residential buildings, specifically the case of multi-family houses from the 1970s in Western Germany. About 2.4 million dwellings and more than 13% of the entire multi-family housing stock in West Germany are located in multi-family houses from the 1970s, in many cases still without any major refurbishment measures until now. A large portion of this stock was or will be subject of portfolio deals often involving foreign investors. Using data from housing corporations, more than 13,700 energy certificates and expert interviews as well as a secondary analysis of a representative survey of housing demand in Germany the key building characteristics and needs for action for this type of the building stock are identified. Further, the specific requirements of the main target groups are found. The results show prioritized refurbishment measures including improvements of thermal insulation (e.g. roof, exterior walls), energy supply, bathrooms, balconies, house entrance areas as well as the structuring of outdoor facilities. The empirical results are useful for property owners like housing corporations, municipalities, owner communities or foreign investors in Western Germany and other European countries to find fundamental and demand-oriented refurbishment measures for their buildings.