Energy Cost Estimator
Estimate annual energy costs by EPC rating and see how upgrades could save money.
Estimate your annual energy costs based on EPC rating and property size. See how upgrading your EPC rating could reduce your bills.
Understanding EPC ratings and energy costs
An Energy Performance Certificate (EPC) rates a property's energy efficiency from A (most efficient) to G (least efficient). The rating directly affects your energy bills — a well-insulated property with modern heating (rated A or B) can cost less than half the energy bills of a poorly insulated one (rated E, F, or G).
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Since April 2020, rented properties in England and Wales must have a minimum EPC rating of E. Properties rated F or G cannot legally be rented out without a valid exemption. In January 2026 the government confirmed it will raise the minimum to the equivalent of C for all private tenancies by 1 October 2030, with a £10,000 cost cap per property — subject to Parliament approving the regulations.
The most cost-effective improvements are typically loft insulation, cavity wall insulation, and upgrading to a more efficient boiler. These can move a property from D to C or even B, saving hundreds of pounds per year.
Frequently asked questions
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How are energy costs estimated?
Estimates are priced on the Ofgem cap Oct–Dec 2026 for typical consumption (the cap's rates already include VAT), adjusted by EPC rating. Better-rated properties use less energy. Costs are further adjusted by number of bedrooms, as larger properties use more energy for heating and lighting.
What does each EPC rating mean in practice?
A-rated homes are highly insulated with renewable energy features — about £780/year for a 3-bed on the Ofgem cap Oct–Dec 2026. D, the commonest rating, is about £1,670/year. F and G properties run to £2,890–£3,560/year and are often draughty older homes with inefficient heating systems.
How much can I save by improving my EPC rating?
Moving from E to C could save around £890/year for a 3-bed home on the Ofgem cap Oct–Dec 2026. The most cost-effective upgrades are insulation (loft and cavity wall), draught-proofing, and upgrading heating controls. Heat pumps and solar panels offer the biggest improvements but at a higher upfront cost.
Is an EPC required when buying or renting?
Yes. Sellers must provide an EPC before marketing a property. Landlords must have a valid EPC (minimum rating E) to let a property. An EPC is valid for 10 years. The certificate includes a list of recommended improvements and their estimated impact.
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Estimates only, based on the assumptions you enter and current published rates. Not financial advice. Your actual costs depend on your circumstances and your lender. HomeThink is not authorised or regulated by the Financial Conduct Authority and recommends no lender or mortgage.
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