How Much Is Needed? Discussion on Benchmarks for Primary Energy Input and Global Warming Potential Caused by Building Construction

The operational energy efficiency of new buildings in the EU should be at the level of ultra-low or near-zero energy buildings. It is therefore relatively difficult to achieve further energy savings. However, the pre-operational phase—raw material sourcing, manufacturing, transportation, and construction—offers significant energy savings and greenhouse gas reduction opportunities, referred to as embodied energy and equivalent CO2 emissions. Unlike operational energy, no standard or legislative criteria have yet been established for embodied energy. Setting maximum embodied energy values converted to the unit of heated building area, accounting for building shape factor, and differentiating between high-mass and lightweight constructions are proposed. This study illustrates assessing environmental indicators based on building shape, highlighting the necessity of relative assessments over absolute values to favour energy efficiency. It also emphasizes that precise criteria should derive from authentic data collected during the energy certification and building permitting processes. Integrating assessments of embodied energy and operational energy demand facilitates a comprehensive evaluation of buildings’ environmental performance.