Raw materials consumption and demolition waste generation of the urban building sector 2016–2050: A scenario-based material flow analysis of Vienna

Cities are substantial consumers of raw materials and producers of waste. For this reason, a number of cities including Vienna, defined in their sustainable development strategies a reduction of the raw material consumption as a sustainability target. As the majority of raw materials consumed by cities are used in the building construction sector, buildings play a key role to achieve this target. While many raw material reduction strategies of cities focus on demolition waste recycling, only few studies also consider the reduction of this waste by avoiding the demolition of buildings. Using the case study of Vienna, this article presents the investigation of three urban development scenarios with respect to the demolition of buildings for the time span 2016–2050. The first scenario projects the business-as-usual from the past years (1991–2015), the second foresees a higher demolition of buildings and substitution by new ones, and the third assumes a zero-demolition of selected old buildings, but extensive renovation toward higher thermal insulation standard and attic-extension of these. The results show that in comparison to the year 2015, the business-as-usual reduces the raw material consumption for building construction by −26%, the demolition scenario by −17%, and the renovation scenario by −35%. On a per-capita basis, the reductions are higher. While these results indicate that the renovation scenario is the most suitable to contribute to the sustainable urban development targets in cities like Vienna with respect to the reduction of the consumption of raw material for building construction, further investigations are required to define other measures to finally achieve this target. Furthermore, environmental impacts and land-use of such urban development scenarios should be investigated. •Many cities including Vienna aim to reduce their resource consumption until 2050.•The largest resource consumption by cities are construction materials for buildings.•Scenarios for resource consumption of Vienna’s building sector are evaluated.•Demolishing less buildings will reduce the materials consumption of Vienna.•Protection and renovation of old buildings is needed to preserve material resources.