The UK has 4.5 million solid-wall terraced houses, and most leak heat like a sieve. Onward Homes and SBS have just committed £9.5M to fix 500 of them in Merseyside, a rare example of a deep retrofit tackling the hardest-to-treat stock. For the homeowner of a Victorian terrace in Manchester, Liverpool or Newcastle, this is the kind of project that proves the work can be done. The question is: at what cost, and who pays?
As reported by Construction UK Magazine, the programme focuses on solid-wall terraced homes where standard cavity insulation is impossible. The work combines external wall insulation, new heating systems, and ventilation upgrades. It is not glamorous. It is essential.
Why terraced houses are a retrofit nightmare
Solid walls conduct heat roughly twice as fast as cavity walls. The Energy Saving Trust estimates that insulating a solid-wall terrace can save £400–£700 a year on heating bills, but the upfront cost typically runs £10,000–£15,000 for external wall insulation alone. Add a heat pump, new radiators and ventilation, and the total can hit £30,000–£40,000 per home. That is a decade or more of payback without subsidy.
The Merseyside scheme benefits from scale, bulk buying materials, standardised designs, and a single contractor. Individual homeowners cannot replicate that. Yet the principle holds: if you own a solid-wall terrace, the only way to get to EPC band C or above is a deep retrofit, not a quick fix.
Who qualifies for help, and who doesn’t
Onward Homes is a housing association, so its tenants and leaseholders get the work for free. Private homeowners in similar properties face a different picture. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. The Boiler Upgrade Scheme covers £7,500 off a heat pump, but that still leaves a gap of £20,000 or more for the full fabric upgrade.
Ofgem has confirmed that the Energy Company Obligation (ECO4) is the main route for low-income households in hard-to-treat homes. It can cover external wall insulation and heating upgrades, but the eligibility criteria are strict: you must be on means-tested benefits or have a health condition worsened by cold. The government has not yet announced a universal retrofit scheme for the 2025–2030 period.
What a typical 3-bed terrace owner should do now
First, check your EPC. If your property is solid-wall and rated D or below, the most cost-effective first step is usually loft insulation (if not already done) and draughtproofing, costing under £500 and saving £100–£200 a year. Next, investigate ECO4 eligibility via your energy supplier. Third, get a quote for external wall insulation from a TrustMark-registered installer; the cost will be sobering, but it is the only way to get a lasting improvement.
The Merseyside programme shows that the technology works. The catch is that without a national retrofit strategy that covers middle-income homeowners, the majority of the UK’s 4.5 million solid-wall terraces will remain hard to treat for another decade.
Homeowners in similar properties should contact their local authority’s energy team now. Some councils have topped up ECO funding with local grants. The window for the current round of Boiler Upgrade Scheme funding closes on 31 March 2027. If you wait, you may find the scheme replaced by something less generous.
Frequently Asked Questions
Yes, but mainly through ECO4 if you are on low income or benefits. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. For higher incomes, there is no universal grant; you would need to pay privately, though some local authorities offer top-up funding.
Typically £20,000–£40,000 depending on property size and whether you include a heat pump. External wall insulation alone is £10,000–£15,000. The Energy Saving Trust estimates annual bill savings of £400–£700, so payback without subsidy is 10–15 years.
