The number of buyers who say an EPC rating will influence their house purchase has jumped to 68%, according to a survey released this week. That is up from 42% in 2021, before energy prices doubled and mortgage rates tripled. For homeowners considering a sale in the next five years, the message is clear: a low rating is now a financial liability, not a bureaucratic box to tick.
The research, commissioned by a property website and reported by Yahoo Finance UK, found that EPC band C has become the baseline expectation. Buyers are walking away from D-rated properties unless the price drops by £10,000 or more. That is not an abstract trend, it is already reshaping asking prices in parts of the South East and East Midlands.
What a low EPC rating costs a typical household
The Energy Saving Trust estimates that a semi-detached home rated EPC D uses about 14,000 kWh of gas per year. The same home upgraded to band C uses roughly 11,000 kWh. At current price cap rates, 6.24p per kWh for gas, the difference is £187 a year. But that is just the direct fuel saving. The bigger cost is the mortgage penalty.
Several major lenders now offer a 0.1% to 0.3% rate discount for homes rated C or above. On a £250,000 mortgage, that saves £250 to £750 annually. Combined with the energy saving, a D-rated home costs its owner between £437 and £937 more each year than a C-rated equivalent. Over a five-year mortgage fix, that is up to £4,685, enough to pay for cavity wall insulation and a new boiler twice over.
Who qualifies for grants, and who does not
The Great British Insulation Scheme, launched in 2023, targets low-income households in the lowest-rated homes. It covers cavity wall, loft, and underfloor insulation. But the eligibility thresholds are tight: only households with an EPC rating of D or below and a council tax band A to D in England qualify. That excludes roughly 40% of owner-occupiers, many of whom live in older, draughtier properties.
The Boiler Upgrade Scheme, meanwhile, offers £7,500 off a heat pump, but only for properties with good insulation. If your home is EPC D or lower, you may need to spend £5,000 to £10,000 on fabric upgrades before the heat pump works efficiently. The grant does not cover that preparatory work. So a homeowner in a D-rated Victorian terrace faces a catch-22: they cannot get the heat pump grant without insulation, and they cannot afford the insulation without a separate grant.
What this means for sellers and buyers
For anyone planning to sell in the next three years, an EPC upgrade is likely to deliver a net return. The average cost to move from D to C, loft insulation top-up, cavity wall fill, draught-proofing, and a modern condensing boiler, runs from £3,000 to £6,000. The uplift in property value, estate agents report, is typically £8,000 to £15,000 in most regions. The catch is timing: the work takes 4 to 8 weeks, and the installer shortages in some areas mean booking 3 months ahead.
Buyers, for their part, should request the full EPC report, not just the front-page rating. It lists recommended improvements with costs and payback periods. A D-rated home with a clear upgrade path to C (loft insulation at £500, draught-proofing at £200) is a better bet than a D-rated home that needs a new heating system and solid wall insulation at £15,000.
What to do next
Check your EPC at gov.uk using the property postcode. If it is D or below, get three quotes for the cheapest recommended measure, usually loft insulation or draught-proofing. Book the work before October, when installers get busy with winter callouts. If you are selling, aim to complete the upgrade before listing. If you are buying, factor the upgrade cost into your offer. The market is already pricing in the difference.
Frequently Asked Questions
Typical costs range from £3,000 to £6,000 for a 3-bed semi, depending on whether you need cavity wall insulation, loft insulation top-up, draught-proofing, or a new boiler. Each measure has a different payback period; loft insulation usually pays for itself within two years.
Yes. Nationwide, Barclays, and Santander currently offer lower rates for homes rated A to C. The discount is typically 0.1% to 0.3%, which on a £200,000 mortgage saves £200 to £600 per year. Some lenders also cap the maximum loan-to-value ratio on D-rated properties.
