• First application of German ecological scarcity method in prospective LCA for buildings. • Integrated LCA and ESM using the German ecological scarcity method. • Multi-objective optimization reveals trade-offs beyond GHG emissions. • Policy-based weighting exposes environmental displacement effects. • Heat pumps and hydrogen aid in balanced environmental performance. The building and construction sector is a major contributor to environmental impacts such as climate change, accounting for a significant share of global energy use, greenhouse gas (GHG) emissions, and resource consumption. In Germany, non-residential buildings alone are responsible for 9% of national GHG emissions. This study evaluates sustainable energy system alternatives for a university campus using an integrated approach that combines energy system modelling, epsilon constraint method, life cycle assessment applying the ecological scarcity method—a policy-based weighting approach specific to Germany. Scenarios for 2020 and 2030 are analysed to assess trade-offs between costs, GHG emissions, and environmental impact scores. The results reveal that minimizing GHG emissions generally reduces environmental impacts but can exacerbate specific issues such as land use, air and water pollutants. In contrast, scenarios optimized for the environmental impact score distribute impacts more evenly across environmental indicators, achieving a more balanced outcome. Medium-cost alternatives, irrespective of the optimization target, tend to increase certain environmental impacts, underscoring the need for significant investments to fully transform non-residential buildings. This research contributes to the understanding of sustainable energy, supporting the broader objective of achieving clean and affordable energy under policy-aligned frameworks.
Lewerenz et al. (Tue,) studied this question.