Abstract
Buildings exert substantial pressure on global resources and contribute significantly to waste and greenhouse gas (GHG) emissions. With ambitious targets like Austria’s aim for climate neutrality before 2050, assessing the large-scale potential of circular economy strategies is essential for policymaking. However, previous studies at the national level lack details about building components and materials. Using an integrated material flow analysis and prospective life cycle assessment model, three measures are assessed for reducing the embodied GHG emissions of Austria’s building stock by 2050: extending building lifespans through renovation, reusing components and recycling materials. Renovation offers the most robust potential, consistently reducing cumulative embodied GHG emissions by 13–15% across all future scenarios. Component reuse provides a more modest 5–8% reduction, with its effectiveness limited by a material mismatch between existing and future buildings, especially under alternative construction scenarios. The potential of recycling is highly variable (3–10%), performing best with a decarbonised energy mix but showing minimal benefit if future construction shifts to low-impact materials. Further work is needed to analyse potential trade-offs from these strategies, such as the impact of lifespan extension or component reuse on the energy efficiency of buildings.
Policy relevance
Clear guidance is provided to policymakers for reducing embodied GHG emissions in the building sector. Building on the European Union’s energy-focused renovation wave, the results call for a complementary ‘preservation-driven’ renovation effort. Extending the lifespan of existing buildings proves the most reliable circular economy strategy for reducing embodied emissions, delivering consistent benefits across future scenarios. Policy incentives should therefore go beyond improving energy efficiency to also preserve and adapt buildings that are economically underperforming or lack aesthetic appeal. Such measures would establish both energy- and preservation-driven renovation as the foundation of Austria’s path to a climate-neutral building stock, supported by component reuse and material recycling to maximise overall reductions. The insights gained can inform similar efforts in other countries with mature building stocks.