More than 15 million homes in the UK have an Energy Performance Certificate (EPC) rating of D or below, reflecting a significant gap in national energy efficiency standards, according to newly released data from rental experts, UNCLE.
With an average EPC rating of 68, most UK homes fall into category D or low C, meaning there’s considerable room for improvement. Only 0.4% of homes, around 99,000 properties, currently meet the top A rating standard.
Where homes perform well (and where they fall short)
According to recent data, Milton Keynes ranks highest in terms of energy-efficient housing, with over 60% of homes achieving an EPC rating of C or above. This trend is partly attributed to a high proportion of new-build properties in the area. Other locations with relatively high performance include Peterborough (55.6%), Westminster (54.5%), and Cambridge (54.1%).
Conversely, Blackpool has the lowest energy performance, with 74.1% of homes rated between D and G. Other areas with lower efficiency include Southend-on-Sea (69.7%), Bradford (68.8%), and Stoke-on-Trent (64.1%).
This geographic variation highlights how local housing stock, construction dates, and renovation trends influence energy efficiency levels.
To better understand how homeowners might improve their EPC ratings, UNCLE consulted Luke Wooffindin of Safe Guard Plumbing, who shared several recommendations:
“Replacing an old non-condensing boiler with a high-efficiency condensing model can significantly improve a property's EPC rating. Modern systems typically exceed 90% efficiency, while older models may only reach 60–70%.”
Estimated costs include:
£1,500–£2,500 for the boiler itself
£500–£1,500 for installation, depending on complexity
Smart heating controls, such as Nest or Hive thermostats, are also increasingly common upgrades.
“These systems offer zoned control and scheduling, which can help manage energy use more effectively. EPC assessments often take these features into account.”
Costs include:
£250–£400 for a smart thermostat
£20–£40 per thermostatic radiator valve (TRV)
Lastly, pipe insulation is a relatively low-cost improvement that can prevent heat loss, particularly in lofts, garages, and unheated spaces.
“At around £2 to £5 per metre, pipe insulation can be a cost-effective way to retain heat and improve efficiency.”
Looking ahead
While EPC ratings were once considered a formality during home transactions, they are becoming more important. This is particularly relevant for landlords, as current regulations are set to require EPC ratings of C or above for all new rentals by 2028 and for existing rentals by 2030 in England and Wales.
Improving a home’s energy efficiency may involve upfront investment, but doing so can lead to more manageable energy bills, increased comfort, and future-proofing against regulatory changes.
