More than half of homes in England and Wales have an Energy Performance Certificate (EPC) rating of D or below according to new analysis that highlights the scale of the UK’s housing efficiency challenge.
Research by Emperor Paint found that 55% of properties fall into EPC bands D to G, raising concerns about the readiness of the nation’s housing stock ahead of planned changes to energy performance assessments and tougher standards for rented homes.
The findings come as the government prepares to overhaul the EPC system, introducing a new Home Energy Model (HEM) that will assess homes across four key areas: fabric performance, heating systems, smart readiness and energy costs.
At the same time, landlords face increasing pressure to improve property efficiency. Rental homes in England and Wales are expected to require the equivalent of an EPC rating C under the new framework from October 2030, up from the current minimum standard of E.
ENERGY INEFFICIENT HOMES
The Isles of Scilly was found to have the highest proportion of energy inefficient homes, with almost 85% of properties holding an EPC rating of D or below.
Gwynedd ranked second, where more than 74% of homes fell into the lower energy performance bands, followed by Pendle at just over 74%.
Other local authorities appearing in the top ten included Ceredigion, Castle Point, Blackpool, Barrow-in-Furness, Hyndburn, Eden and Copeland.
The research analysed EPC data covering domestic properties in England and Wales between January 2008 and February 2026.
The figures are likely to concern landlords and homeowners facing potentially significant investment requirements over the coming years as government policy increasingly focuses on improving housing efficiency and reducing carbon emissions.
HEAT RETENTION
Jack Reading of Emperor Paint says: “Changes to energy performance certificates mean that they will now be based on how properties retain heat, rather than how much energy a property uses.
“The new system will assess factors including fabric performance, heating systems, smart readiness and energy costs, placing greater focus on the physical condition and thermal performance of the property.”
Reading argues that moisture management and wall performance could become increasingly important as weather patterns change and homes face greater exposure to prolonged wet conditions.
EXTREME WEATHER
He adds: “As weather conditions become more extreme, with warmer summers and wetter winters, exterior wall coatings not being included in EPC ratings represents a growing gap in how home energy efficiency is measured in the UK.
“Without accounting for how walls perform in real, weather-exposed conditions, EPC scores risk overlooking a key factor influencing heat loss.”
The findings underline the scale of the retrofit challenge facing the UK’s ageing housing stock as policymakers seek to improve energy efficiency and reduce household energy consumption over the coming decade.
