Simulating demography and housing demand in an urban region under scenarios of growth and shrinkage

摘要

After the fall of the Berlin wall in 1989, demographic decline and urban shrinkage brought massive changes in the housing stock in East German cities. Urban planners and policy makers face complex problems caused by the resulting vacancies and demolitions and the handling of urban brownfields in the inner city. At the same time, cities are under ongoing pressure of suburbanisation. Because existing models focus mainly on demographic and urban growth and their impact on housing stocks, we present a simulation model that is able to compute both growth and shrinkage processes. We uncover nonlinear dynamics and feedbacks between demography, housing preference, and supply of housing space. The simulation results show that, despite population decline, the increasing number of single households leads to a growing total housing demand in the central parts of the study area. Beyond this area, residential vacancies in multistorey housing segments will remain regardless of population growth. At the same time, the simulations show that, despite population shrinkage and an overall oversupply of flats, there is a negative net demand for flats in affordable prefabricated housing estates as the percentage of low-income households increases. These findings will help planners modify or adapt their visions of the residential function in shrinking cities and to adjust current programmes of renewal and restructuring.