Consumer advocacy group Which? has raised concerns about the reliability of Energy Performance Certificates (EPCs), calling for significant reforms. Introduced in 2007, EPCs are designed to assess and rate the energy efficiency of homes on a scale from A (most efficient) to G (least efficient).

A recent Which? investigation included EPC assessments for 12 homeowners in England, Wales, and Scotland between February and March 2024. The results revealed widespread inaccuracies and unhelpful advice. In one instance, an assessor failed to mention a property’s solar panels and wood-burning stove, while another homeowner was advised to spend £26,700 on upgrades that would take 29 years to recoup.

Which? highlighted that EPC ratings influence property sale prices and eligibility for government grants and green financial products. Among the 12 homeowners assessed, only one was satisfied with their EPC, and eight reported inaccuracies. In Aberdeenshire, a couple’s solar panels and wood-burning stove were omitted from their report, and another assessment overlooked draught-proofing despite evident needs.

Rocio Concha, Which?’s director of policy and advocacy, urged the next government to improve the EPC system’s reliability and usefulness. Recommendations include auditing training requirements for EPC assessors and revising certificates to offer clearer, actionable advice.