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House Roadmap

EPC ratings, explained properly

Your certificate is a modelled estimate of what the property costs to run per square metre — not a measurement of how much energy you use, and not a measure of carbon. Once you know what it is actually scoring, improving it stops being guesswork.

The SAP scale

1–100
  1. A92–100
  2. B81–91
  3. C69–80
  4. D55–68
  5. E39–54
  6. F21–38
  7. G1–20

Band boundaries are fixed in the regulations. The score is modelled, so two assessors can land a few points apart on the same house.

  • Homes below band C

    51.6%

    England and Wales, 2024. C is the band most policy aims at

  • Most common band

    D

    37.1% of homes

  • A certificate lasts

    10 years

    Even if the property changes

  • Cheapest point on the scale

    £45

    Low energy lighting, per SAP point gained

Illustrative. Band shares are ONS figures for homes in England and Wales with a certificate, 2024. The cost per point is a placeholder, as are the point gains further down.

The bands

What each letter actually means

The letter is a band of SAP points, and the points are a model of running cost per square metre. The summary column is what a home in that band usually looks like in practice.

EPC bands, score ranges and share of homes
BandScoreWhat it usually meansShare of homes
A92–100New build to the current standard, or a deep retrofit. Rare enough to be remarkable.0.4%
B81–91Modern, well insulated and usually heated by a heat pump or a very efficient boiler.15.1%
C69–80The target band for most policy. Insulated cavity walls, a good boiler, decent glazing.33%
D55–68The most common band in England and Wales. Something significant is missing — usually wall insulation.37.1%
E39–54Solid walls, an old boiler, or both. The legal floor for a new private tenancy.11.8%
F21–38Uninsulated and often off the gas grid. Expensive to heat and expensive to fix.2.1%
G1–20Little or no insulation, and frequently electric room heaters. Cannot be let without an exemption.0.6%

Running costs are the certificates' own estimate of heating, hot water and lighting, averaged over the homes in each band. They assume standard occupancy and the fuel prices the method used when each certificate was lodged, so they compare bands rather than predict a bill.

Illustrative. Shares are ONS figures for England and Wales, 2024. Running costs are from the EPC register, England and Wales, each home's latest certificate. The summaries are placeholders.

Where the UK sits

Band D is the national default

Two things decide a property's band before anyone touches it: when it was built, and whether the walls can be filled. Everything else is detail.

Homes in England and Wales by band

Bars wear the band colour, and each one prints its letter — the colour never carries the value on its own.

  1. A0.4%
  2. B15.1%
  3. C33%
  4. D37.1%
  5. E11.8%
  6. F2.1%
  7. G0.6%

Bands C and D together hold 70% of the stock. The policy question is how much of D can be moved into C without touching the walls.

Band by the decade the home was built

Share of homes in each band group, by construction period. One hue, darker means more.

BuiltA–BCDEF–G
Before 19001.3%16.1%43.5%27.6%11.5%
1900–19290.6%23.8%51.3%20%4.3%
1930–19491%26.9%52.4%16.3%3.4%
1950–19662.3%38.5%44.8%11.8%2.6%
1967–19752.4%39.5%44.7%11.4%2%
1976–19823%52.6%35.9%7.4%1.1%
1983–19903.5%51.9%37.7%6.2%0.8%
1991–20024.2%58.2%33.3%4%0.4%
2003–201126.5%66%6.5%0.9%0.1%
2012 onwards79.3%17.2%2.8%0.6%0.1%

Band C becomes the norm for homes built from 1976, and most homes built since 2012 are A or B. Homes with no recorded age are left out.

Walls

Share of homes in England and Wales, as the certificate found it.

  1. Cavity, filled40.9%
  2. Cavity, partly filled2.2%
  3. Cavity, empty12.1%
  4. Solid, insulated2.4%
  5. Solid, uninsulated22.1%
  6. Built to a modern standard13.7%
  7. Timber, system built or other6.6%

25.9% of cavity walls are still empty or partly filled, and 90.4% of solid walls have no insulation.

Roofs and lofts

Share of homes in England and Wales, as the certificate found it.

  1. Loft, no insulation8.1%
  2. Loft, under 100 mm6.8%
  3. Loft, 100 to 199 mm17.9%
  4. Loft, 200 mm or more29.6%
  5. Loft, depth not recorded5%
  6. Flat roof, roof rooms or thatch4.3%
  7. Built to a modern standard10.4%
  8. Another home above17.8%

22.1% of lofts have less than 100 mm of insulation.

Glazing

Share of homes in England and Wales, as the certificate found it.

  1. Single glazed3.5%
  2. Partly single glazed7.1%
  3. Double glazed88.7%
  4. Secondary glazed0.4%
  5. Triple glazed0.2%

10.7% of homes have some single glazing left.

Heating controls

Share of homes in England and Wales, as the certificate found it.

  1. Thermostat and TRVs60.7%
  2. Thermostat, no TRVs14.3%
  3. TRVs, no thermostat12%
  4. No thermostat or TRVs4.5%
  5. Storage heater controls4.7%
  6. Heater thermostats only3.9%

18% of homes with radiators have no room thermostat.

The four nations, side by side

Scotland rates best of the four, largely because its stock has a higher share of post-war cavity-walled housing and a longer record of publicly funded insulation programmes.

  • EnglandMedian bandC
  • WalesMedian bandD
  • ScotlandMedian bandC
  • Northern IrelandMedian bandD
  • AA
  • BB
  • CC
  • DD
  • EE
  • FF
  • GG

Illustrative. England and Wales are ONS band shares for 2024, with median bands from the EPC register. Scotland and Northern Ireland are from their own registers, each home counted once from its latest certificate. The heatmap by age is England and Wales from the EPC register, leaving out homes with no recorded age.

Improving yours

What certificates ask for, and what the method says it costs

The register records what each assessor recommended and what the method allows for it. The two rankings barely overlap: the measures recommended most often are the cheap ones, and the ones that would change how the house feels sit near the bottom.

How often it is recommended

Share of homes whose latest certificate asks for the measure.

  1. Solar panels66.4%
  2. Floor insulation49.5%
  3. Low energy lighting throughout37.4%
  4. Solid wall insulation24%
  5. New condensing gas boiler20.3%
  6. Heating controls and TRVs16.6%
  7. Cavity wall insulation16.1%
  8. Loft insulation to 300mm12%
  9. Double glazing (from single)9%
  10. Air source heat pump0%

A certificate recommends what would raise its rating, by the rules of the year it was lodged. Measures added to the method recently appear on far fewer certificates for that reason alone.

What the method allows

The range the middle recommendation was given, cheapest first.

  1. Low energy lighting throughout£210–£245
  2. Heating controls and TRVs£220–£250
  3. Loft insulation to 300mm£900–£1,200
  4. Cavity wall insulation£900–£1,500
  5. New condensing gas boiler£2,200–£3,500
  6. Double glazing (from single)£4,500–£6,000
  7. Floor insulation£5,000–£10,000
  8. Solar panels£8,000–£10,000
  9. Solid wall insulation£7,500–£11,000
  10. Air source heat pump£5,000–£30,000

The same figure for every home, so it is a guide rather than a quote. The cheapest measures on a certificate are the ones that do least for comfort.

Improvement measures with how often they are recommended, the method's cost and the evidence an assessor needs
MeasureRecommended toThe method's cost
Solar panelsMCS certificate and the declared array size. Orientation and shading are modelled, not measured.66.4%of homes£8,000–£10,000
Floor insulationInstaller certificate. Suspended timber floors only.49.5%of homes£5,000–£10,000
Low energy lighting throughoutCounted bulb by bulb at survey. Genuinely worth doing the week before an assessment.37.4%of homes£210–£245
Solid wall insulationInstaller certificate, or visible evidence at survey. Undocumented work scores nothing.24%of homes£7,500–£11,000
New condensing gas boilerGas Safe notification and the model's efficiency rating.20.3%of homes£2,200–£3,500
Heating controls and TRVsVisible at survey. The cheapest points on the certificate.16.6%of homes£220–£250
Cavity wall insulationCIGA or installer guarantee. A filled cavity with no paperwork is assumed unfilled.16.1%of homes£900–£1,500
Loft insulation to 300mmMeasured depth at survey, so this one is hard to lose on paperwork.12%of homes£900–£1,200
Double glazing (from single)FENSA or equivalent certificate, with the installation date.9%of homes£4,500–£6,000
Air source heat pumpMCS certificate. Scores less than its running-cost saving suggests, because of how SAP prices electricity.0%of homes£5,000–£30,000

How to improve your rating

How far a typical home is from band C, counted off the register's own score distribution, and what the method allows for each measure that closes the gap.

Read the guide

If you let the property

The minimum standard for a private tenancy, the proposed band C line, the exemptions and the cost cap — with how far the stock actually sits from each.

Read the guide

Costs are the range the middle recommendation was given, from certificates lodged in the year to 9 September 2026: the same for every home, and not quotes. Recommended to is the share of homes whose latest certificate asks for the measure. How many SAP points a measure gains isn't published: the register records the recommendation and its cost, not the modelled gain.

Your ceiling

How far a home like yours can realistically go

Not the certificate's potential score, which assumes every recommendation is done regardless of whether it is possible. This is where the obvious work actually lands.

SAP score, now and after the obvious work

Six reference properties on one scale.

  • Today
  • After the obvious work
  1. Victorian terrace, solid wall52→74
  2. 1930s semi, unfilled cavity58→81
  3. 1960s flat, electric heating49→68
  4. 1980s detached, gas66→86
  5. Rural cottage, oil heated41→69
  6. New build, 2015 onwards82→91

The obvious work means insulation the building can take, a modern heating system and controls. It does not assume a heat pump where there is nowhere to put a cylinder.

  • EC+22 points

    Victorian terrace, solid wall

    Almost all of the gain is in the walls, which is also almost all of the cost.

  • DB+23 points

    1930s semi, unfilled cavity

    The cheapest journey to band C in the country: cavity fill, loft top-up and controls.

  • ED+19 points

    1960s flat, electric heating

    Hard to move. No roof of your own, no room for a cylinder, and communal decisions.

  • DB+20 points

    1980s detached, gas

    Roof area and a decent cavity make solar plus insulation unusually effective here.

Illustrative. Placeholder figures to show what this page will hold. Real ranges arrive with the quote and performance data behind them.

What it gets wrong

Six things the certificate does not tell you

None of this makes an EPC useless. It makes it a specific instrument with known limits, which is a different thing from the way it is usually quoted.

  • It is a cost rating, not a carbon one

    The band is driven by modelled energy cost per square metre. That is why a heat pump can lower your emissions and barely move your band, and why electricity prices moving would re-rate the whole country without a single home changing.

  • Assumed, not measured

    An assessor spends 30 to 60 minutes in the property. Anything they cannot see or evidence is assumed from the age and type of the building, and the assumptions are deliberately pessimistic.

  • Undocumented work scores nothing

    Insulation you cannot prove is treated as absent. Finding the certificate for cavity fill done in 2009 is often worth more points than a weekend of actual work.

  • Floor area does a lot of the work

    The rating is per square metre, so a large home with poor fabric can outscore a small one with good fabric. It is not a measure of how much energy you will use.

  • Two assessors, two answers

    The same property assessed twice commonly differs by a few points, and occasionally by a band, depending on what was evidenced and which defaults were applied.

  • The recommendations are generic

    The improvement list is generated from the software's rules, not from a survey of what your home actually needs. Treat it as a prompt, not a plan.

The rules

Where your band stops being paperwork

For an owner-occupier the certificate is mostly advisory. For a landlord it is a legal floor, and for anyone claiming a heat pump grant it is a gate.

Where this page's answers come from

  • EPC Register — every certificate lodged in England, Wales and Northern Ireland
  • Scottish EPC Register — the equivalent north of the border
  • RdSAP — the reduced assessment procedure that produces the score
  • English Housing Survey and the Scottish and Welsh equivalents — stock by age and type
  • DESNZ — minimum energy efficiency standard consultations

Last checked against these sources on 17 September 2026.

  1. 1 April 2018

    In force

    Band E minimum for new tenancies

    Private landlords could no longer grant a new tenancy on a property rated F or G without registering an exemption.

  2. 1 April 2020

    In force

    Band E minimum for all tenancies

    Extended to existing tenancies, with a cost cap on the work a landlord can be required to fund.

  3. 15 May 2025

    In force

    Boiler Upgrade Scheme insulation test

    The grant turns on your certificate's recommendations, so an EPC with outstanding loft or cavity advice can block a heat pump claim.

  4. 1 April 2028

    Proposed

    Band C proposed for new tenancies

    Consulted on rather than legislated. If it lands, roughly half the private rented stock needs work, and the queue for installers starts well before the date.

  5. 1 April 2030

    Proposed

    Band C proposed for all tenancies

    The full extension, with a higher cost cap. Landlords with solid-walled stock are the ones facing a real bill rather than a paperwork exercise.

Questions

Common questions about EPCs

How long does an EPC last?

Ten years. It stays valid even if you change the property, which is why a certificate can be badly out of date and still be the one on the register. Anything that relies on your band — a grant, a tenancy, a sale — is worth a fresh assessment first.

What does an EPC cost?

Typically £60 to £120 for a house, more for a large or unusual property. It is not regulated, so quotes vary by a factor of two in the same town.

Can I improve my band without spending much?

Sometimes several points, yes. Low energy bulbs throughout, visible heating controls, a measurable loft depth and — above all — producing the certificates for insulation already installed are all cheap. They do not make the house warmer, which is the honest caveat.

Why did my heat pump barely change my rating?

The rating models cost per square metre, and electricity costs roughly three to four times as much per unit as gas. A heat pump that uses far less energy can still model as costing about the same to run, so the points gained are modest.

Does the recommended improvements list tell me what to do?

Not really. It is generated automatically from the software's rules and takes no view on your property's construction, your budget or the right order. It is a starting point for questions, not a plan.

Who can produce an EPC?

An accredited domestic energy assessor, registered with a government-approved scheme. Anyone can check an assessor's registration, and the certificate itself is public on the EPC register.

Can I challenge a rating I think is wrong?

Yes. Go to the assessor first with the evidence they missed — insulation certificates, glazing paperwork, boiler documents. If that fails, their accreditation scheme has a complaints process that can require a re-assessment.

See the certificate for your address

We'll pull the current rating, what it was scored on and the realistic ceiling for a property built like yours.

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