Absolute environmental sustainability assessment applied to energy-positive buildings

The building sector exerts significant pressure on planetary systems and must align with environmental limits. Although life cycle assessment (LCA) supports eco-design, it mainly enables relative comparisons and does not determine whether a building is sustainable in absolute terms. Absolute environmental sustainability assessment (AESA) addresses this limitation, but its application to energy-positive buildings remains methodologically challenging. This study proposes a consistent AESA methodology for buildings that export renewable electricity, combining attributional LCA with a system-expansion approach applied to both impacts and carrying capacities. A dwelling per occupant carrying capacity is defined and extended to account for energy export. The framework is demonstrated through a residential case study in France. The case study shows that the dwelling’s ability to comply with the planetary-boundary carrying capacity depends on its positive energy balance and the use of bio-based materials. The approach supports the practical integration of AESA into building eco-design and encourages maximising the energy production capacity of residential buildings.