How to improve your EPC rating
The rating is a model of what the property costs to run per square metre, so improving it means changing what the model sees. Some of that is real work on the building, and a surprising amount of it is evidence for work somebody already did.
The median home below band C
Half the homes still below band C score above this, half below. At 9 points the question is which measure to pick, not whether the house needs rebuilding — and the chart on this page shows how long that tail runs.
Homes below band C
49.7%
Of homes with a certificate in England and Wales
Within five points of C
33.6%
Of the homes below it. A small job, not a retrofit
Median score
69
Band C, from each home's latest certificate
Cheapest measure the method allows
£20–£40
Hot water cylinder
EPC register, England and Wales, certificates to 9 September 2026, each home counted once from its latest certificate. Costs are the range the middle recommendation was given: the method's standard figure, the same for every home, and not a quote.
How far to C
Most homes below band C are not far below it
Band C starts at 69 SAP points. The register records every certified home's score, so the distance to that line is countable rather than a matter of opinion — and for a large share of homes it is a few points.
How many points short of band C
Homes in England and Wales scoring below 69, by the gap to it.
Peak: 11–20 points 2,587,363
Points are not evenly priced. The first few usually come from lighting, controls and evidence; the last ten usually come from the walls.
1–3 points
21.1%Lighting, controls and finding the paperwork
4–6 points
18.1%One real measure, usually loft or cavity
7–10 points
18.9%Two measures, or one substantial one
11–20 points
25.6%Fabric work, and probably the heating too
Over 20
16.3%A retrofit, not an improvement
21.1% of homes below band C are within three points of it — 2,127,740 homes. At that distance the question is usually which recommendations on the existing certificate are already done and never evidenced, rather than what to build next.
What's missing
What assessors actually find, and what the method allows to fix it
Before asking which measure gains most, it is worth knowing which are still outstanding across the stock. These are the things certificates record as absent, with the method's own cost for each beside them.
Share of homes where it is still missing
England and Wales, as the assessor found or assumed it.
- Cavity walls still empty or part filled25.9%
- Solid walls with no insulation90.4%
- Lofts under 100mm22.1%
- Homes with some single glazing10.7%
- Wet systems with no room thermostat18%
Each share is of the homes the question applies to: empty cavities as a share of cavity-walled homes, thin lofts as a share of homes with a loft.
| Measure | The method's cost | Still missing |
|---|---|---|
| Cavity wall insulation | £900–£1,500 | 25.9% |
| Solid wall insulation | £7,500–£11,000 | 90.4% |
| Loft insulation | £900–£1,200 | 22.1% |
| Double glazing | £4,500–£6,000 | 10.7% |
| Heating controls | £220–£250 | 18% |
The measures
What certificates ask for, most often first
This is the ranking the register supports: how many homes have the measure on their latest certificate, and what the method allows for it. It is not a ranking by points gained, because nobody publishes that.
| Measure | Recommended to | The method's cost | What the assessor needs to see |
|---|---|---|---|
| Solar panelsMCS certificate and the declared array size. Orientation and shading are modelled, not measured. | 66.4%of homes | £8,000–£10,000 | MCS certificate and the declared array size. Orientation and shading are modelled, not measured. |
| Floor insulationInstaller certificate. Suspended timber floors only. | 49.5%of homes | £5,000–£10,000 | Installer certificate. Suspended timber floors only. |
| Low energy lighting throughoutCounted bulb by bulb at survey. Genuinely worth doing the week before an assessment. | 37.4%of homes | £210–£245 | Counted bulb by bulb at survey. Genuinely worth doing the week before an assessment. |
| Solid wall insulationInstaller certificate, or visible evidence at survey. Undocumented work scores nothing. | 24%of homes | £7,500–£11,000 | Installer certificate, or visible evidence at survey. Undocumented work scores nothing. |
| New condensing gas boilerGas Safe notification and the model's efficiency rating. | 20.3%of homes | £2,200–£3,500 | Gas Safe notification and the model's efficiency rating. |
| Heating controls and TRVsVisible at survey. The cheapest points on the certificate. | 16.6%of homes | £220–£250 | Visible at survey. The cheapest points on the certificate. |
| Cavity wall insulationCIGA or installer guarantee. A filled cavity with no paperwork is assumed unfilled. | 16.1%of homes | £900–£1,500 | CIGA or installer guarantee. A filled cavity with no paperwork is assumed unfilled. |
| Loft insulation to 300mmMeasured depth at survey, so this one is hard to lose on paperwork. | 12%of homes | £900–£1,200 | Measured depth at survey, so this one is hard to lose on paperwork. |
| Double glazing (from single)FENSA or equivalent certificate, with the installation date. | 9%of homes | £4,500–£6,000 | FENSA or equivalent certificate, with the installation date. |
| 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 | MCS certificate. Scores less than its running-cost saving suggests, because of how SAP prices electricity. |
A certificate recommends what would raise its rating under the rules of the year it was lodged, so measures added to the method recently appear on far fewer certificates for that reason alone. How many SAP points each one gains is not published: the register holds the recommendation and its cost, never the modelled gain, and a number in that column would be ours rather than the method's.
The order
Evidence, then cheap, then fabric, then heat
The sequence matters because the method is a model. Two of the five steps below change nothing about how the house feels, and they are the two that move the score for the least money.
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.
Find the paperwork first
Insulation you cannot evidence is scored as absent. The certificate for cavity fill done in 2009, the FENSA numbers for the windows, the installer's guarantee for the loft — each of those is worth points for the cost of a phone call.
Do the cheap visible things
Low energy bulbs throughout, thermostatic valves on the radiators, a room thermostat. They are counted at survey, they cost very little, and they are the difference between a borderline D and a C.
Insulate what can be insulated
Loft to current depth, cavity fill where the cavity is clear, underfloor where the floor is suspended timber. These are the measures with the best ratio of points to pounds in the method.
Then look at the heating
A modern boiler and good controls, or a heat pump. A heat pump scores less than its running-cost saving suggests, because the method prices electricity against gas — which is a criticism of the method, not of the heat pump.
Book the assessment last
The certificate lasts ten years and describes the house on the day. Doing the work and then getting assessed is obvious; a surprising number of people do it the other way round and pay for two.
Paperwork
The points that cost nothing, and the ones that cost everything
An assessor spends under an hour in the property and scores what they can see or evidence. Everything else is assumed from the age and type of the building, and the assumptions are deliberately pessimistic.
Free points
- Installer certificates for insulation already in place
- FENSA or equivalent numbers for the glazing
- A measurable loft depth, not a hatch nobody opened
- Boiler make, model and year, so the real efficiency is used
- Access to the cylinder and its jacket
Expensive points
- Solid wall insulation, which is most of the cost of most retrofits
- Whole-house glazing replacement from single
- Anything that needs scaffolding, twice
- Changing the heating fuel when the fabric is still leaking
What the certificate thinks it saves
Across the register, homes model at £981 a year now and £735 with every recommendation done — a 25% cut.
That is a modelled figure at standard occupancy and the fuel prices of the year each certificate was lodged. It compares homes honestly and predicts a bill badly.
Questions
Common questions about improving an EPC
How do I get my EPC from D to C?
Band C starts at 69 SAP points, so the question is how many points short you are. 21.1% of homes below C are within three points of it, and at that distance the answer is usually evidence and cheap measures rather than building work: certificates for insulation already installed, low energy lighting throughout, and a room thermostat with thermostatic valves. Beyond about seven points it normally takes insulation the house does not yet have.
What improves an EPC rating the most?
For most homes, wall insulation — which is also the most expensive thing on the list. The register does not publish points per measure, so nobody can honestly rank them by gain. What it does publish is which measures certificates recommend and what the method allows for each, which is the table on this page.
How many points is each measure worth?
Not published, anywhere. The EPC register records the recommendation made and the indicative cost the method allows, never the modelled point gain. Sites that print a points-per-measure table have estimated it. We would rather say that than join them.
Can I improve my rating without doing any work?
Often by several points. Anything the assessor cannot see or evidence is treated as absent, so producing the paperwork for insulation that already exists is the single highest-return thing most people can do. It makes the certificate more accurate rather than the house warmer, which is the honest caveat.
Will a heat pump improve my EPC?
Usually yes, but by less than the running-cost saving implies. The rating models cost per square metre and electricity costs several times what gas does per unit, so a heat pump that uses far less energy can still model as costing about the same to run. That is a property of the method rather than of the heat pump.
What is the typical home starting from?
A median SAP score of 69, which is band C. Half of all certified homes in England and Wales are below that.
What the bands mean and where the method parts company with reality is on the EPC guide. If you let the property, the minimum standards are on the landlord page. The measures themselves are covered in insulation, heat pumps and solar panels.
See what your certificate says
We'll pull the current rating for an address, what it was scored on, and which of its recommendations are still outstanding.