Material Efficiency of Housing in Times of Demographic Change – Evidence from Case Study Research into two German Municipalities

Abstract

Housing and construction have a significant impact on the consumption of resources of any society. At the same time, on all policy levels strategy documents towards sustainable development highlight the importance of improvements in resource efficiency. Against this background, this contribution presents results of research on the impact of demographic trends and changing user preferences on the use of resources within the housing sector with a focus on construction materials. The material intensity of different types of housing (in particular detached homes vs. apartment buildings) are quantified under different development scenarios drawn on the basis of two medium sized German case study municipalities showing declining and stagnating population development. Among other, the results indicate that the per capita stock of construction materials within the housing sector remains either stable or may even increase despite a falling population. With respect to alternative development scenarios, our results show, that under the condition of a stable or growing population a shift of housing supply from single-family (detached) homes towards a higher share of multi-unit residential buildings can contribute to a more efficient use of materials. An interesting option under the condition of a declining population is the conversion of a potentially growing number of vacant single-family homes into smaller multi-unit/multi-purpose residential buildings since it can help to avoid vacancy and keep otherwise wasted resources in use.