What Does EPC Rating F Mean? And How to Improve It
If your EPC certificate shows a band F rating, your home is in the bottom 10% of homes in England for energy efficiency. It is not the worst rating (that is G), but it is well below average. The good news: F-rated homes qualify for significant grant support, and the improvements to reach band E or D are well understood and usually cost-effective.
EPC Rating F means your home has an energy efficiency score of 21 to 38 out of 100. Band F is well below average and is below the current legal minimum for rental properties (band E). A typical F-rated home costs £2,200 to £3,000 per year to heat. Around 10% of English homes are rated F, and they qualify for significant grant support.
EPC band F at a glance
Where does F sit on the EPC scale?
The EPC scale runs from A (most efficient) to G (least efficient). Each band corresponds to a range of SAP scores out of 100:
Source: MHCLG English Housing Survey 2023/24, percentage of English housing stock by EPC band.
What does an F rating actually tell you?
An F-rated home typically has several of these characteristics:
Walls
Either solid walls (pre-1930s) with no insulation, or cavity walls that have never been filled. Walls are the biggest source of heat loss in most homes, accounting for around 35% of total heat loss. This is usually the single biggest factor in an F rating.
Windows
Often single-glazed or very old double glazing with failed seals. Draughty window frames compound the problem. Replacing single glazing with modern double glazing can gain 4-8 EPC points.
Heating
Usually an older gas boiler (possibly non-condensing) or outdated electric storage heaters. Heating controls are often basic or absent. An old boiler can waste 30% or more of the gas it burns compared to a modern condensing model.
Loft insulation
Either missing entirely or well below the recommended 270mm. Some F-rated homes have just 25-50mm of old insulation, which barely makes a difference. Topping up to 270mm is cheap and effective.
Bills
At Ofgem Q2 2026 rates (electricity 24.67p/kWh, gas 5.74p/kWh), an F-rated home typically costs £2,200 to £3,000 per year to heat. That is £500-£1,400 more than the UK average of £1,641.
How does F compare to G?
F is bad, but it is not the worst. Compared to band G:
Band F (score 21-38)
- 5% of English homes
- Bills: £2,200-3,000/year
- Usually has some improvements (partial insulation, basic double glazing)
- Cheaper to fix: £8,000-20,000
Band G (score 1-20)
- 3% of English homes
- Bills: £3,000-4,000+/year
- Typically no improvements at all
- More expensive to fix: £15,000-30,000+
Both F and G are below the MEES minimum for rental properties. Both qualify for the same grant schemes. But F-rated homes are generally cheaper and easier to improve because they often have at least some existing measures to build on.
What does F mean for landlords?
F-rated properties are illegal to rent
The MEES minimum for rental properties is band E (score 39+). An F-rated property is below this threshold. You cannot grant a new tenancy on an F-rated property unless you have spent up to the cost cap trying to improve it and registered a valid exemption.
From October 2030, the minimum rises to band C. So the minimum journey is F to E now, but plan for F to C by 2030.
See our landlord MEES compliance guide for the full details.
How to improve an F-rated home
There are three realistic improvement targets from band F:
F to E: the legal minimum for landlords
Gaining enough points to reach score 39+. Often achievable with loft insulation, draught-proofing, and heating controls. Cost: £1,500-£5,000, often covered by grants.
F to D: significant bill savings
Reaching score 55+. Usually requires wall insulation or a boiler upgrade on top of cheaper measures. Cost: £5,000-£12,000. Annual savings of £400-800.
F to C: the 2030 target
Reaching score 69+. A more comprehensive retrofit including wall insulation, full loft insulation, modern heating, and possibly double glazing. Cost: £8,000-£20,000, with significant grant support available.
| Improvement | Typical cost | EPC points | Annual saving |
|---|---|---|---|
| Loft insulation (to 270mm) | £400-£800 | 4-8 | £150-£280 |
| Draught-proofing | £100-£300 | 1-3 | £60-£100 |
| Heating controls (thermostat + TRVs) | £150-£350 | 2-4 | £75-£120 |
| Cavity wall insulation* | £0-£500* | 8-15 | £200-£350 |
| Condensing boiler replacement | £2,000-£3,500 | 8-15 | £250-£450 |
| Solid wall insulation (internal) | £5,500-£8,500 | 10-20 | £300-£500 |
| Double glazing | £3,000-£7,000 | 4-8 | £80-£180 |
* Cavity wall insulation is often free or heavily subsidised through GBIS/ECO schemes. EPC point gains are approximate and vary by property. Sources: Energy Saving Trust, BRE SAP methodology.
The quickest path to band E
For an F-rated home scoring around 30 that needs 9 points to reach E:
Loft insulation (5 pts) + heating controls (3 pts) + draught-proofing (2 pts) = 10 points for under £1,200.
If you have unfilled cavity walls, cavity wall insulation alone (8-15 points) could jump you straight to D or beyond, and it is often free through GBIS.
Grants for F-rated homes
F-rated homes are high priority for government and supplier-funded energy efficiency schemes:
ECO4 / Warm Homes Plan
Targets the worst-rated homes (E, F, G) with funded retrofit packages. Can cover wall insulation, loft insulation, heating system replacements, and more. Eligibility is based on income or benefits, with local authority flex routes also available.
Great British Insulation Scheme (GBIS)
Free insulation for qualifying households. F-rated homes in lower council tax bands can qualify without income checks. Covers cavity wall, loft, floor, and room-in-roof insulation.
Boiler Upgrade Scheme (BUS)
£7,500 towards an air source heat pump. Worth considering if your boiler is at end of life, but insulate the property first for best results.
See our full grants guide for eligibility details and how to apply.
Our honest take on EPC band F
F is a poor rating. Your home is losing heat through walls, roof, windows, and gaps that should have been addressed years ago. You are paying hundreds of pounds more per year than you need to on energy bills. In cold weather, rooms furthest from the boiler are probably noticeably cold.
But F is also very fixable. Unlike G-rated homes that often need everything doing at once, many F-rated homes can make a big jump with two or three targeted improvements. If you have unfilled cavity walls, one free GBIS grant could transform your rating overnight.
The key message: do not ignore it. The grants available now are generous, and the improvements will pay for themselves in lower bills, better comfort, and a more valuable property. Start with our postcode checker to see exactly what your EPC recommends and what grants you could claim.
Check your specific property
Every F-rated home is different. A 1950s semi with unfilled cavities is a completely different job from a Victorian terrace with solid walls. Your EPC certificate lists the specific improvements recommended for your property, with indicative costs.
Check your EPC rating and recommendations
Enter your postcode to see your EPC rating, what improvements are recommended, and what grants you could claim. Free, instant, no sign-up.
Other EPC rating guides
Sources
- MHCLG — English Housing Survey 2023/24 (EPC distribution by band)
- BRE — SAP methodology (EPC scoring)
- Energy Saving Trust — Home improvement savings estimates
- Ofgem — Energy price cap Q2 2026 (electricity 24.67p/kWh, gas 5.74p/kWh)