From Nearly Zero-Energy Buildings (NZEBs) to Zero-Emission Buildings (ZEBs): Current status and future perspectives

• NZEB energy performance levels vary widely across the EU countries. • NZEB levels for new buildings are about 30 % more demanding than for renovation. • Renewable energy contribution in NZEBs varies from 9 % to 55 %, with some gaps in quantification. • Few countries currently include GHG emissions requirements in their NZEB definitions. • Member States need to enhance NZEB requirements to meet ZEB standards as of 2030, particularly to achieve zero on-site carbon emission. The building sector holds a relevant position in decreasing greenhouse gas (GHG) emissions within the European Union (EU). The revised Energy Performance of Buildings Directive (EPBD), recently adopted, sets forth ambitious goals to make the EU building stock carbon–neutral by 2050. Currently, the Nearly Zero-Energy Building (NZEB) standard remains mandatory for all new buildings from 2021 to 2030. This paper assesses the progress of Member States in implementing NZEB standards, based on extensive data collection and harmonization. The findings reveal that the NZEB concept is well-established and average energy performance has improved by about 10 % over the past four years. New NZEB have about 30 % lower energy demand than renovation to NZEB level. However, many countries still lag behind in meeting recommended benchmarks, particularly when looking at the non-renewable energy demand. Looking ahead, the 2024 revised EPBD sets Zero-Emission Building (ZEB) as the goal for all new buildings starting in 2030. The paper explores how ZEB requirements might evolve from current NZEB definitions. Projections suggest that future ZEBs, which are 10 % more ambitious than existing NZEB levels for total primary energy demand, would show better alignment with recommended benchmarks. However, the renewable energy contribution in NZEBs vary from 9 % to 55 %, and integrating enough renewables to meet the ZEB standard of zero on-site carbon emissions remains a challenge. In some countries, the high total primary energy demand can further complicate this goal. The conclusion highlights the need for stricter energy thresholds and further integration of renewables to achieve ZEB requirements.