Science for Policy: Insights from Supporting an EU Roadmap for the Reduction of Whole Life Carbon of Buildings

Abstract

Abstract The European Union (EU) aims at climate-neutrality by 2050, necessitating a transformation of the entire economy, including the construction and buildings sectors. This study, initiated by the European Commission’s DG ENV, provides a basis for a roadmap to mitigate building-related greenhouse gas (GHG) emissions from a life cycle perspective. This paper presents methodological developments and findings for the baseline year 2020. The research assesses whole life cycle (WLC) GHG emissions from European buildings, covering various archetype buildings. It supports the creation of an EU roadmap to reduce WLC GHG emissions by 2050. The study employed attributional LCA and five key steps: 1) Characterization of building stock based on four climatic regions; 2) Selection of representative archetypes; 3) Modelling of building life cycle inventories; 4) life cycle assessment using the GWP indicator; 5) Upscaling of building results to the building stock level. The results emphasize the relevance of reducing both operational and embodied GHG emissions at both the individual building and building stock level. At the level of individual new buildings with advanced energy performance, embodied GHG emissions average 66% of life cycle emissions, ranging from 43% to 97%. At stock level, embodied GHG emissions make up 21% of whole life cycle GHG emissions, even though only about 1% of building stock area is newly constructed in the baseline year. The remaining 79% of WLC emissions are coming from the operation of existing buildings. Within the embodied emissions, new building production and construction process stages account for 55%, existing building’s use phase embodied contributes another 20%, and refurbishment of the existing stock makes up around 15%, while end-of-life processes contribute only 2%. The study provides a novel perspective on GHG emission in the life cycle of buildings and building stocks. It lays the groundwork for an EU roadmap to reduce WLC GHG emissions. Outcomes will aid policy formulation, target setting, and implementation of suitable GHG emission reduction strategies.