The average cost to retrofit a hard-to-treat home has a new benchmark: £27,700. That is the per-property figure emerging from a £9.5m programme targeting 343 homes across Merseyside, as reported by LABM Weekly. The scheme, funded by the government’s Social Housing Decarbonisation Fund, will install solid-wall insulation, heat pumps, solar panels, and new windows in social housing properties across Liverpool and Wirral.
Who qualifies, and who doesn’t
The programme is reserved for social housing tenants. Owner-occupiers in adjacent streets will not see a penny. That matters because 60% of UK homes with solid walls are privately owned, according to the Energy Saving Trust. The government’s own figures show only 7% of solid-wall homes have been insulated, compared with 80% of cavity-wall homes. The Merseyside scheme, while welcome, illustrates the chasm between public-sector ambition and the private-homeowner reality. Grants such as ECO+ and the Great British Insulation Scheme cover cavity-wall and loft insulation but typically pay only £1,000–£3,000 per home for solid-wall work. The gap between that and £27,700 is not a rounding error, it is a policy failure.
What it costs a typical 3-bed semi
Ofgem’s typical domestic consumption values put a 3-bed semi at 12,000 kWh of gas and 2,900 kWh of electricity per year. A home with solid walls and single glazing could lose 35% of its heat through the walls alone. Retrofitting to EPC band C, the target for the Merseyside homes, typically requires external wall insulation (£10,000–£15,000), a heat pump (£7,000–£13,000 after the Boiler Upgrade Scheme grant), and solar panels (£5,000–£7,000). That totals £22,000–£35,000, consistent with the £27,700 average. The catch: most government schemes pay per measure, not per whole-house plan. A homeowner applying for a heat pump grant cannot also claim the full cost of insulation under a separate scheme. The system is fragmented, and the paperwork is brutal.
What this means for your EPC and resale value
An EPC upgrade from band D to C adds an estimated £10,000–£15,000 to a property’s value, according to Nationwide Building Society research. For a homeowner spending £27,700, the equity gain covers roughly half the cost. The rest is a bet on lower energy bills. Ofgem’s price cap for October 2024 will be £1,717 a year for a typical dual-fuel household. A retrofit to EPC C could cut that by 30–40%, or £515–£687 annually. The payback period on the full £27,700 is 40–54 years, longer than most homeowners plan to stay. That is why the Merseyside scheme is funded by grants, not loans. Private homeowners need a different model: low-interest green mortgages, council tax rebates, or stamp-duty discounts tied to EPC improvements. None exist at scale yet.
What to do now
Check your EPC certificate for wall type. If it says “solid” and your heating is gas, start with a free cavity-wall and loft insulation assessment via the Energy Saving Trust. Next, get quotes for external wall insulation from three certified installers, not general builders. The Merseyside scheme uses a whole-house approach; you can too, but you will need to stitch together grants yourself. The Boiler Upgrade Scheme offers £7,500 for a heat pump until 2028. Apply before you insulate: the heat pump will be sized for the pre-retrofit heat loss, and you may need a bigger, more expensive, unit. Insulate first, then size the heat pump for the lower demand. That saves thousands.
Frequently Asked Questions
Yes, but funding is limited. The Great British Insulation Scheme covers solid-wall insulation only for households on certain benefits. ECO+ offers some support for low-income homes. Most private homeowners pay full cost, typically £10,000–£15,000, and recoup it through lower bills over 15–20 years.
It is realistic for a solid-wall, gas-heated 3-bed semi with single glazing. Costs vary by region and property size. The figure includes external wall insulation, heat pump, solar panels, and windows. A simpler retrofit, loft insulation, cavity-wall fill, and a new boiler, costs under £5,000 and improves EPC by one or two bands.
