An Energy Performance Certificate rates your property from A (most efficient) to G (least efficient). Since 2008, every property in England and Wales needs a valid EPC when it’s sold, let, or built. It lasts 10 years. For most homeowners, it’s been something you get done and forget about. But for landlords, it’s become a legal requirement that can cost serious money to comply with — and for buyers, it’s increasingly affecting property values and mortgage rates.
The A to G Scale
Each letter corresponds to a SAP (Standard Assessment Procedure) score:
- A (92–100): Extremely efficient. Very rare in existing homes — mainly new-builds with heat pumps and solar.
- B (81–91): Highly efficient. Well-insulated modern homes.
- C (69–80): Above average. The government’s target for all homes by 2035.
- D (55–68): Average. This is where most UK homes sit.
- E (39–54): Below average. Currently the minimum for rental properties.
- F (21–38): Poor. Illegal to rent out without an exemption.
- G (1–20): Very poor. Also illegal to rent out.
About 40% of English homes are rated D, 20% are C, and another 20% are E or below. If your home is a Victorian terrace with solid walls and single glazing, you’re probably looking at D or E.
What Landlords Need to Know
Since April 2020, it’s been illegal to rent out a property rated below E (the Minimum Energy Efficiency Standards, or MEES). Fines of up to £5,000 for letting an F or G property. Since April 2023, this applies to all existing tenancies, not just new ones.
The government has consulted on raising the minimum to EPC C — originally targeted for 2025, now delayed. But it’s likely coming, and the cost of upgrading from E to C can be significant, particularly for older properties with solid walls.
What Affects Your Rating?
The EPC assessment looks at:
- Wall insulation: Cavity, solid (insulated or not), timber frame
- Roof insulation: Loft insulation depth and quality
- Windows: Single, double, or triple glazing
- Heating system: Boiler type, age, efficiency
- Hot water: How it’s heated and stored
- Lighting: Proportion of LEDs
- Renewables: Solar panels, heat pumps, etc.
Worth knowing: the EPC doesn’t measure your actual energy bills or how you use the property. It’s a theoretical assessment of the building itself. A wasteful occupant in an A-rated home can spend more than a careful one in an E-rated home.
How to Improve Your Rating
Most cost-effective improvements:
- Loft insulation top-up (to 270mm): £300–£500, improves by 1–2 points
- Cavity wall insulation: £500–£1,500, improves by 5–15 points
- LED lighting throughout: £50–£200, often worth 1–3 points
- Smart heating controls: £200–£400, improves by 2–4 points
- New boiler: £2,500–£4,000, improves by 5–15 points if replacing an old one
- Solar PV panels: £5,000–£8,000, can jump you 10–20+ points
The cheapest wins are loft insulation and LEDs. Often enough to bump you up a full band for under £500.
EPC and Property Value
Research from DESNZ suggests homes rated A or B sell for roughly 5–10% more than equivalent D or E homes. Mortgage lenders are also starting to offer “green mortgage” products with lower rates for energy-efficient homes. The financial incentive to improve your rating is growing year on year.
Check Your EPC
You can look up any property’s current EPC for free on the EPC Register (epcregister.com). Our EPC rating tool helps you understand what your current score means and which improvements would give you the biggest bang for your buck.