Pilot study on functional segregation through post-compaction


The booming housing market in major German cities is leading to the displacement of commercial enterprises from the city centres

First results from the ongoing joint pilot study by ILS, RWI and RWTH Aachen University

Growing population figures and real estate investments in recent years had led to a strong demand for building land, particularly in major German cities. One of the consequences of their shortage is the increased densification of existing quarters through new buildings and uses. This slows down the growth of the city and protects valuable natural, recreational or agricultural areas. The densification of existing urban quarters is also in line with the model of the compact European city. It is the prerequisite for ensuring that as many uses as possible are accessible to residents directly in the quarter. Among other things, this reduces urban traffic or makes it easier to shift to walking, cycling or public transport.

The pilot study "Change of use in quarters through redensification" conducted by scientists at the Institute for Regional and Urban Development Research (ILS) in Dortmund, the RWI Leibniz Institute for Economic Research in Essen and the RWTH Aachen University shows that in recent years, German cities have mostly experienced a loss of diversity of use in urban areas that have been particularly affected by redensification. The researchers investigated the extent to which the relationship between industrial sites and residential use had changed in the six largest cities in Germany in areas characterised by commercial or residential use with high development dynamics. The results show that commercial and residential areas were displaced by residential areas, even if these processes took place with varying intensity. Only in a few of the areas studied can a reverse trend be observed, i.e. housing is being displaced by business. However, most of these areas are outside the inner city districts, which indicates the displacement of business from integrated urban locations to peripheral urban areas.

The statements are based on the evaluation of raster data and satellite images of the cities of Berlin, Düsseldorf, Frankfurt, Hamburg, Cologne, Munich and Stuttgart. The data sets provide information on the number of different types of use (residential and commercial) in digital grids of the individual urban areas. For the study, rooms with relatively strong changes in the number of residential and commercial premises were considered. For this purpose, data from 2005 and 2015 were compared with each other and corresponding developments were assigned to two central types. These include areas that were previously characterised to varying degrees by commercial or residential use. For both types, a different degree of displacement of commercial by residential areas and a simultaneous increase in the density of use could be observed. The results of the entire pilot study should be published in 2020.

Project team

  • Junior professor Jan Polívka, Sophie Doerner, Diane Matuschek
    Research Group Spatial Planning and Urban Design (Adaptive Urban Systems) at the Institute for Regional and Urban Development Research & Department of Sustainable Housing Stock Development RWTH Aachen University
  • Hermann Rappen
    Competence Area Growth, Business Cycle, Public Finance at RWI Leibniz Institute for Economic Research
  • Canan Çelik
    Chair of Urban Planning and Design and Institute of Urban Planning and European Urbanism, RWTH Aachen University



Canan Çelik

Academic Staff, Research Coordinator


+49 241 80 95026