Overview of EU building envelope energy requirement for climate neutrality

Building energy policies play a key role in reducing energy consumption in the EU building sector towards climate neutrality goals. This study conducts a comparative analysis of building regulations across EU Member States, with a focus on the building envelope efficiency. It examines thermal transmittance limits for windows, walls, floor, and roof to highlight regulatory differences and propose ways to improve harmonization. Challenges arise from the lack of a centralised data source, needing reliance on national regulations and similar studies to fill gaps and increase compliance with the Energy Performance of Buildings Directive (EPBD). Integrating data from various sources, including national reports and scientific literature, the study clarifies the current regulatory landscape for new and existing buildings, stressing the importance of improving the efficiency of the building envelope to minimise energy losses, and includes national climate zones for comprehensive coverage of regional climates. Variability in regulations underlines the need for a higher uniformity. Suggested steps include the development of a unified climate zone system, the establishment of guidelines for each zone, and the definition of harmonized thermal transmittance limits to facilitate a consistent regulatory framework. While this study focuses primarily on thermal transmittance, it provides a basis for future research efforts to address differences in European building codes and progress towards climate neutrality. Future developments could include the analysis of additional parameters to provide a holistic view of building energy performance and regulations supporting sustainability goals in the EU.