What does an EPC measure?

An EPC measures the energy efficiency of your home on an A to G scale. It is based on the building fabric (walls, roof, floors, windows), heating system, insulation, and lighting. The assessment uses the RDSAP methodology to calculate a standardised rating.

What is an EPC? | Energy Certificates Guide

Q: When do you need an EPC?

You need an EPC when selling a property (legally required before marketing), renting (before a new tenancy starts), on completion of a new build, when applying for ECO grants, and for commercial to residential conversions. Failure to have one can result in fines of up to £5,000.

Q: How long is an EPC valid?

An EPC is valid for 10 years from the date it is issued. You can get a new one at any time, and it is worth doing so if you have made energy efficiency improvements to your property since the last assessment.

Q: What happens during an EPC assessment?

A qualified assessor visits your property for 30 to 60 minutes. They check the walls, roof, floors, windows, doors, boiler, heating controls, lighting, and hot water system. They measure room dimensions and take photos. The assessment is non-invasive and the certificate is lodged on the national register within 24 hours.

Q: What is the minimum EPC rating for landlords?

Under the Minimum Energy Efficiency Standards (MEES), rental properties must have a minimum rating of E before a new tenancy can start. Fines for non-compliance can reach up to £30,000.

What an EPC measures

An EPC assesses how energy-efficient your property is and gives it a rating from A to G. The rating is based on the building fabric (walls, roof, floors, and windows) as well as your heating system, insulation levels, and lighting. Every domestic EPC in England uses the RDSAP (Reduced Data Standard Assessment Procedure) methodology, which produces a standardised score so properties can be compared fairly.

A

92-100 · Most efficient

B

81-91

C

69-80

D

55-68 · UK average

E

39-54

F

21-38

G

1-20 · Least efficient

EPC ratings run from A (most efficient) to G (least efficient). The average UK home is rated D.

What your EPC report includes

Your EPC is more than just a letter grade. The full report gives you a detailed breakdown of your property's energy performance and actionable recommendations.

Current rating: where your property sits now on the A to G scale
Potential rating: the rating you could achieve with recommended improvements
Estimated energy costs: annual running costs broken down by heating, hot water, and lighting
Recommendations: specific improvements ranked by cost and potential impact on your rating
Environmental impact: your property's CO2 emissions rating, also scored from A to G

When do you need an EPC?

An EPC is legally required in several situations. Not having one when you need it can result in a fine of up to £5,000.

Selling a property: you must have a valid EPC before you can market your home. Estate agents cannot legally list a property without one.
Renting a property: landlords must provide an EPC to tenants before a new tenancy begins. This applies to new tenancies and renewals.
New builds: a new-build property requires an EPC on completion, before anyone moves in.
ECO grants: an EPC is needed to assess eligibility for government energy efficiency schemes such as the ECO4 programme.
Commercial to residential conversions: properties being converted from commercial to residential use need an EPC before occupation.

How long is an EPC valid?

An EPC is valid for 10 years from the date it is issued. There is no requirement to renew it during that period unless you are selling or letting and want an updated rating.

You can get a new EPC at any time. It is worth getting a fresh one if you have made improvements since your last assessment, such as installing a new boiler, adding insulation, or upgrading your windows, as these changes could move you into a higher rating band.

What happens during an EPC assessment?

A qualified Domestic Energy Assessor visits your property for between 30 and 60 minutes, depending on the size of the home. The assessment is non-invasive. Nothing is taken apart or damaged. We cover properties across Swanley, Dartford, Bromley, Bexley, Greenwich, and Sidcup.

During the visit, the assessor checks:

Walls: construction type, thickness, and insulation
Roof and loft: insulation type, depth, and coverage
Floors: construction and insulation
Windows and doors: glazing type, age, and condition
Boiler: make, model, age, and fuel type
Heating controls: thermostat, programmer, and TRVs
Lighting: percentage of low-energy bulbs
Hot water system: cylinder insulation and heating method

The assessor also measures room dimensions and takes photos for the records. Your certificate is then lodged on the national register within 24 hours and we send you a link to view it.

EPC ratings explained

Each rating band tells a story about your home. Here is what each one really means:

A

92–100

The overachiever

Your home is so efficient it practically generates its own energy. Think solar panels, triple glazing, and a heat pump humming away. Your energy bills are the envy of the street.

B

81–91

The high performer

Either a well-built new home or an older one that has had serious upgrades. You have done the work and your energy bills show it. Buyers love you.

C

69–80

Above the curve

Better than most. You have got decent insulation and a modern-ish boiler. This is where the government wants all rental properties to be in the near future.

D

55–68

The UK average

Welcome to the club. Most UK homes land here. Typically built between the 1950s and 1990s with some insulation but room for improvement. A few targeted upgrades could bump you to a C.

E

39–54

The bare minimum

Below average, but still legal to rent out. If you are a landlord, this is the current floor. You are probably feeling the pinch on energy bills, and a few improvements could make a real difference.

F

21–38

Needs attention

Your home is losing heat faster than you can pay for it. If you are a landlord, you cannot legally rent this out without an exemption. The good news: improvements at this level often have the biggest impact.

G

1–20

The fixer-upper

The least efficient rating. Your energy bills are doing the heavy lifting. But every improvement counts, and moving from G to E or D is very achievable with the right upgrades.

Minimum EPC ratings for landlords (MEES)

The Minimum Energy Efficiency Standards (MEES) set the lowest EPC rating that a property can have before it can be legally rented out.

Current law

Rental properties must have a minimum rating of E before a new tenancy can start. Properties rated F or G cannot be let unless the landlord has registered a valid exemption.

Penalties: Fines for letting a property that does not meet the minimum standard can reach up to £30,000, depending on the length of the breach and the rateable value of the property.

How to improve your EPC rating

There are several practical and cost-effective ways to boost your EPC score. Common improvements include adding loft or cavity wall insulation, upgrading to a modern condensing boiler, switching to LED lighting, and installing better heating controls. Many of these changes pay for themselves through lower energy bills within a few years.

Read our full guide to improving your EPC rating →

If you are selling, you need a valid EPC before your estate agent can list your property. Read our guide to EPCs when selling →

EPC for landlords
Minimum ratings, penalties, exemptions, and the Renters' Rights Act

EPC when selling
Legal requirements, how ratings affect buyers, and when to book