Jessica Few, Despina Manouseli, Eoghan McKenna, Martin Pullinger, Ellen Zapata-Webborn, Simon Elam, David Shipworth and Tadj Oreszczyn
This analysis compares the difference between the Energy Performance Certificate (EPC)-modelled and smart meter measured annual energy use on a like-for-like basis in 1,374 gas-heated British households selected from the Smart Energy Research Lab (SERL) Observatory. EPCs and metered energy use were converted to primary energy use intensity to provide a comparison of the same quantity for the first time.
We show that EPCs predict substantially and significantly more energy use than metered in homes in Great Britain. EPC bands A and B show no statistically significant difference, but all other bands show a statistically significant and increasing gap as EPC rating decreases. Average energy use in low efficiency bands is very similar, despite large differences in EPC-modelled energy use. This difference persists after removing homes matching the EPC model assumptions regarding occupancy, thermostat set-point and whole-home heating; suggesting that differences in modelled and actual behaviour are unlikely to fully explain the discrepancy.
EPCs are a core tool in the residential energy sector, and the gap between EPC-modelled and metered energy use could have a significant impact on policy, research and industry. Future research should investigate this discrepancy and its implications, and action should be taken to improve EPCs.
Few, J., Manouseli, D., McKenna, E.J., Pullinger, M., Webborn, E., Elam, S., Shipworth, D. and Oreszczyn, T. 2023. The over-prediction of primary energy use intensity by EPCs in Great Britain: A direct comparison of EPC-modelled and smart metered energy use in gas-heated homes. OSF Preprints. doi: 10.31219/osf.io/jn3v6Opens in a new tabOpen access
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