Atom bank study questions accuracy of EPC ratings

The official methods for assessing household EPC emissions may be overstating the environmental impact of British homes by as much as half, a study reveals.

According to Atom bank, its findings raise concerns about whether current tools can genuinely support the UK’s ambition to reach ‘Net Zero’.

Working with Experian and Durham University, Atom compared predicted emissions based on Energy Performance Certificates with meter readings from more than 1,000 homes.

The results showed a sharp gap between projected and actual carbon output, with properties across different ratings consuming similar amounts of energy.

EPCs don’t reflect actual emissions

Atom’s director of ESG, Edward Twiddy, said: “The UK has made real progress in addressing the challenge of decarbonising its economy but continuing that momentum will require better data and more targeted action.

“This study reveals that EPC ratings do not reliably reflect actual household emissions, with inaccurate data being a clear hindrance to reaching net zero.

“If most households are using similar amounts of energy, the focus should be on where that energy comes from and then how to make that clean energy as affordable as possible.”

He added: “The findings of this trial have important implications for green lending, banks’ carbon reporting, and the future use of EPCs in measuring and reducing residential emissions, which has implications for social issues like fuel poverty.”

EPC green lending questions

The bank’s conclusion challenges the assumption that higher-rated homes consistently perform better and the research highlights weaknesses in using EPCs as a benchmark for both green lending and government policy.

University College London’s Energy Institute noted a similar pattern in national data, suggesting that little difference exists in energy consumption once a home is rated above band C.

The team has been examining the issue for a government study that is yet to be released.

Atom is working with industry body B4NZ to encourage other lenders to share information and press for reforms.

The bank wants EPCs to draw on direct measurements such as smart meter readings rather than theoretical estimates.

It is also calling for cheaper renewable electricity to replace gas as the primary fuel for heating.