Characterization of thermal performance and nominal heating gap of the residential building stock using the EPBD-derived databases: The case of Portugal mainland

• Analyzing EPBD-derived databases provides insights on the EP of the building stock.
• The EPBD-derived databases enable an estimation of the gaps in energy use.
• 80% of the Portuguese buildings have reference heating needs > 100 kWh/m2 year.
• Actual use in 2009 was only 5% of the reference energy for space heating and 22% for DHW.
• Possibly an indication of significant lack of indoor comfort and a health problem.

This work explores the potential of the energy certificates databases, established in EU countries after the EPBD, to characterize the Energy Performance of the residential building stock and the gap between the nominal needs and the actual energy use from the national energy balances, using Portugal mainland as case-study. It also assesses the impact of Portuguese regulations on the thermal quality of the housing building stock through time. The results confirm the viability, usefulness and richness of using the EPBD-derived databases. In the specific case of Portugal they show a mix of natural improvement with boosts from regulations, with crucial developments observed after 2006, reflecting the positive impact of the EPBD. Furthermore, it was concluded that the actual energy use for space heating and for domestic hot water are only 5% and 22%, respectively, of those obtained from the RCCTE reference/“nominal” calculation conditions, with the difference constituting what is here called as the “nominal heating gap”.