What an EPC Actually Covers

An Energy Performance Certificate is a legal document that rates how efficiently a property uses energy and how much carbon dioxide it produces. It is put together by an accredited assessor who visits the property, measures it, notes the construction and heating, and lodges the result on the national register. Certificates are valid for ten years, and you can look up an existing one free of charge by searching the register by postcode.

If you are buying or renting, an EPC must be provided. Landlords are required to make one available to prospective tenants before they commit to anything, so it is fair to ask for it early. If you are searching in Bath, pull the EPC for every property you view — comparing two flats side by side is far more revealing than reading one on its own.

Reading the A to G Scale

The headline is the coloured bar chart you have probably seen on estate agent details. Ratings run from A (most efficient) to G (least), and each band covers a range of scores: A is 92–100, B is 81–91, C is 69–80, D is 55–68, E is 39–54, F is 21–38 and G is 1–20.

Band D is the most common rating in England and Wales, and Bath's housing stock often fares worse. Georgian and Victorian terraces, solid stone walls, original sash windows and converted upper-floor flats with electric heating are all common here, and all tend to score in D, E or F territory. A modern purpose-built flat might sit comfortably in B, so the gap between two similarly sized homes can be substantial.

A poorly rated property costs more to heat and is harder to keep warm. Treat the certificate's own cost figures as a rough comparison tool rather than a bill forecast — they are based on standard assumptions about occupancy, heating patterns and tariffs that rarely match the way you actually live.

The Detail Beneath the Headline Rating

• Element-by-element ratings — walls, roof, floor, windows, main heating, hot water and lighting each get their own assessment, so you can see exactly where the weaknesses lie.
• The potential rating — what the property could reach if every recommendation were carried out. A wide gap between current and potential is a useful clue.
• Recommendations — ranked improvements with indicative costs and typical savings. Some are generic and won't suit every building, but they are a sensible starting point.
• The environmental impact rating — a separate score for carbon emissions, usually similar to the efficiency rating but not always.
• The date — a certificate from 2015 won't know about the boiler replaced in 2021. Always check how current it is.

What Tenants Should Check Before Signing

A low rating isn't an automatic no, but it should shape your questions. Find out what powers the heating and hot water — mains gas, electricity or something else — because a flat with storage heaters and no gas supply can be expensive to run even when the rent looks reasonable. Ask what the current occupants pay for energy across a winter quarter, and ask whether there are heating controls, a cylinder jacket and decent draught-proofing.

Look at the windows and note whether they are single-glazed sashes. In older Bath flats, ask how the property is ventilated; a tightly sealed period building with no trickle vents or extractor fans can suffer from condensation and mould, something the rating alone won't reveal. Remember too that a landlord isn't obliged to act on the recommendations listed, so if winter warmth matters to you, weigh the rating heavily at the viewing stage.

What Landlords Should Do About a Poor Rating

The regulatory floor matters. In England and Wales, rented homes must reach at least band E, with limited exemptions — including listed buildings where improvements would harm the property's character, and homes where no further improvement is possible. There is also a cost cap on landlord-funded works (currently £3,500 including VAT), and the rules are reviewed periodically, so check the latest guidance before budgeting.

Beyond compliance, look at cost-effectiveness. Loft insulation, a cylinder jacket, draught-proofing, thermostatic radiator valves and modern heating controls are usually cheap wins. Replacing an ageing G-rated boiler often delivers the biggest single jump in both rating and tenant comfort.

In Bath, be careful with fabric changes. Fitting internal wall insulation to a solid Bath stone wall without specialist advice can trap moisture and cause real damage, and work to a listed building or one in a conservation area may need listed building consent or planning permission. Speak to the council's conservation team early, not after you've accepted a quote.

Questions Worth Asking

• How old is the EPC, and has anything changed since it was lodged?
• What is the main heating fuel, and how is hot water heated?
• Which single improvement would move the rating up a band for the least money?
• Would any recommended work need listed building consent or building regulations approval?
• For tenants: what did the last occupant actually spend on energy over a winter?

A few minutes spent reading the certificate properly can save a great deal of money and discomfort later. For tenants it turns a vague feeling about a cold flat into hard information; for landlords it turns good intentions about energy efficiency into a clear, costed plan.