Assessing EPC-derived gas consumption estimates using metered data: A case study in Turin

Buildings are major contributors to both energy consumption and carbon emissions, making them a key target for emission reduction. In the European Union, Energy Performance Certificates (EPCs) are widely used in urban building energy modelling; however, EPC-derived estimates may differ from actual consumption, while incomplete coverage limits their application. This study investigates the consistency between EPC-derived natural gas consumption estimates and metered data in Turin, Italy. The analysis covers 128,225 volumetric units, of which 22,551 (17.59%) are associated with at least one EPC. Results show overestimation by EPC-based estimates, with discrepancies exceeding 90% for the least efficient classes. For non-district-heating units, the median EPC estimate for Class G exceeds 230 kWh/m²/y, compared with a metered median of approximately 9 kWh/m²/y. To address these discrepancies, empirical Correction Factors (CFs) are derived for different energy performance classes and building characteristics. The results provide an empirical assessment of EPC-based natural gas consumption estimates at urban scale and demonstrate the potential of data-driven Correction Factors to improve their consistency with measured consumption.