Nearly 1.2 million homes in England and Wales have an EPC rating of F or G, the lowest bands. BuyAssociation Group now suggests these properties could be a bargain for investors and first-time buyers willing to take on a renovation project. As reported by BuyAssociation Group, the logic is simple: pay less upfront, invest in upgrades, and end up with a higher-value, more efficient home. But the arithmetic is not that clean.
Who qualifies, and who doesn’t
The discount on an F or G property can be significant, estate agents report 10-15% below the market price for a comparable C-rated home. On a £250,000 house, that is £25,000 to £37,500 saved at purchase. But the catch is that bringing that home up to a C rating costs, on average, £15,000 to £30,000, according to the Energy Saving Trust. The saving evaporates unless you can do much of the work yourself or tap into grants.
That £15,000–£30,000 figure assumes a typical 3-bed semi needing loft insulation (around £500), cavity wall insulation (£2,000–£3,000), double glazing (£5,000–£8,000), and a heat pump or boiler upgrade (£7,000–£14,000 before grants). If the property has solid walls, external insulation can cost £10,000–£15,000 alone. The Great British Insulation Scheme offers free or discounted insulation for some low-income households, but for most buyers, the full cost lands on their mortgage.
What it costs a typical 3-bed semi
Let’s run the numbers on a real-world example. A 1930s semi-detached in Manchester, EPC F, listed at £180,000. A similar C-rated house down the road sells for £210,000. The buyer saves £30,000 upfront. But the survey reveals single-glazed windows, an old gas boiler, no loft insulation, and uninsulated solid walls. To reach EPC C, the buyer needs:
- Loft insulation: £500
- Cavity wall insulation (if applicable): £2,500
- Double glazing: £6,000
- New boiler or heat pump: £8,000 (after Boiler Upgrade Scheme grant of £7,500 for heat pumps)
- Draught-proofing and other measures: £1,000
Total: £18,000. That leaves a net saving of £12,000, but only if the buyer can finance the work upfront and the house doesn’t need other structural repairs. One in five such homes also has damp or timber issues, adding another £5,000–£10,000. The bargain quickly becomes a liability.
The regulatory clock is ticking
The government’s Energy Performance of Buildings Act, expected in 2025, will require all rental properties to have an EPC C by 2030. Owner-occupiers are not yet forced, but the direction of travel is clear: mortgage lenders are already offering lower rates for higher-rated homes. Barclays, Nationwide, and Virgin Money all have green mortgage products with rates 0.1–0.5% lower for EPC A or B properties. The Bank of England’s Climate Biennial Exploratory Scenario suggests lenders may eventually restrict lending on F and G homes.
BuyAssociation Group’s advice to see low-rated homes as bargains assumes the buyer has the capital and time to renovate. For cash-rich investors, it works. For a first-time buyer stretching to afford a home, the risk is that they end up in a cold, expensive-to-run house they cannot afford to upgrade. Ofgem data shows homes rated F or G cost an average of £1,500 more per year in energy bills than a C-rated home, that is £125 a month before any work begins.
How grants and schemes change the maths
The Boiler Upgrade Scheme offers £7,500 off a heat pump, but only for properties with a valid EPC and no outstanding recommendations for loft or cavity wall insulation. The Great British Insulation Scheme is income-assessed and has a waiting list. The ECO4 scheme targets low-income households and those on certain benefits. For most buyers, the grants cover a fraction of the total cost.
The smartest move is to get a full EPC assessment before exchange of contracts, then a detailed quote from a certified retrofit coordinator. The Retrofit Academy recommends a ‘fabric first’ approach, insulate the building envelope before upgrading the heating system. That sequence is not cheap, but it avoids the trap of installing a heat pump in a draughty house and then wondering why the bills are still high.
What to do next
If you are considering an EPC F or G home, get a full building survey and a retrofit assessment before you commit. Budget at least £20,000 for upgrades to reach EPC C, and check eligibility for the Boiler Upgrade Scheme and Great British Insulation Scheme. Mortgage lenders may require a minimum EPC rating for certain products, so factor that into your affordability calculation. The bargain exists, but only for those who do the maths before the auctioneer’s hammer falls.
Frequently Asked Questions
Yes, most lenders will offer a mortgage, but rates may be higher and some lenders have minimum EPC requirements. Specialist lenders and green mortgages may offer better terms if you commit to upgrades within a set timeframe. Always check with your lender before making an offer.
The cheapest measures are loft insulation (around £500) and draught-proofing (under £200). Cavity wall insulation costs £2,000–£3,000 but can improve the rating by one or two bands. The Energy Saving Trust recommends starting with insulation and then moving to heating upgrades.
