The Boiler Upgrade Scheme pays £7,500 towards an air-source heat pump. In Cornwall, that figure has just jumped to £9,000, the highest local top-up in the country. The Falmouth Packet reported the details this week, and for homeowners in the Duchy the numbers are striking. But the real story is not the headline grant. It is whether enough people will actually take it up before the money runs out.
Who qualifies, and who doesn’t
The £9,000 comes from two pots: the national Boiler Upgrade Scheme (£7,500) and Cornwall’s own Shared Prosperity Fund (£2,000). To get the full amount, you must own a home in Cornwall, have an EPC rated D or above, and hold a valid EPC that shows no outstanding recommendations for cavity-wall insulation or loft insulation. That last condition is a hidden gatekeeper. Of the 280,000 homes in Cornwall, roughly 40% have an EPC below D, according to the latest government data. Another chunk will have uninsulated walls that the assessor flagged but the owner never fixed. The practical pool of eligible households is probably under 100,000.
The scheme is capped at 1,000 installations. At current heat-pump installation rates in the South West, about 150 per month across the region, that cap could be reached within seven months. Cornwall Council expects the money to last until March 2025, but early demand will tell.
What it costs a typical 3-bed semi
A typical air-source heat pump installation for a 3-bedroom semi-detached house costs between £10,000 and £14,000, according to figures from the Energy Saving Trust. After the £9,000 grant, the homeowner pays £1,000–£5,000. That is cheaper than a new gas boiler (£2,500–£4,000 installed) but only just. The running-cost comparison depends heavily on the property’s insulation. A well-insulated home with a heat pump can cut heating bills by 20–30% compared with gas. A draughty one can see bills rise.
Cornwall’s housing stock is older than the national average. Many homes have solid walls, single glazing, and no underfloor insulation. The grant does not cover those upgrades. A homeowner who needs to insulate first could face an additional £5,000–£10,000 bill before they even install the heat pump. The EPC condition already requires that insulation work is done, but it does not pay for it.
EPC impact, and why it matters
A heat pump alone can lift an EPC from D to C, depending on the starting point. Combined with insulation, it can reach B. For a Cornwall homeowner looking to sell or rent, that improvement is worth real money. A one-band EPC uplift adds roughly 3–5% to a property’s value, according to Nationwide’s house-price index. On a £300,000 Cornish terrace, that is £9,000–£15,000. The grant effectively pays for itself in equity gain before the first winter’s heating bill arrives.
But the catch is timing. The grant application must be made before installation, and the installer must be MCS-certified. Cornwall Council estimates the process takes 8–12 weeks from application to commissioning. Homeowners who wait until November will be applying in the middle of the heating season, when installer availability is tightest.
What this means for the rest of the UK
Cornwall’s top-up is a pilot for what other combined authorities could do. The West Midlands, Greater Manchester, and the North East all have Shared Prosperity Fund allocations that could be redirected toward heat-pump subsidies. If the Cornwall scheme hits its 1,000-home target within budget, expect other regions to copy it. If it undershoots, because the eligibility criteria are too tight or the installer capacity too low, the Treasury will use that as evidence that higher grants do not drive uptake.
The government’s own heat-pump rollout target is 600,000 installations per year by 2028. Last year the UK installed roughly 60,000. The gap is not about grant size alone. It is about installer numbers, consumer awareness, and the upfront cost of insulation. Cornwall’s £9,000 grant solves the first problem. The other two remain.
Homeowners in Cornwall should check their EPC now. If it is D or above and the insulation recommendations are ticked off, the financial case for a heat pump has never been stronger. Applications opened on 1 October 2024. The cap of 1,000 homes means early movers will get the money. Those who delay until next spring will almost certainly miss it.
Frequently Asked Questions
No. The grant is only available for new installations. You must not have already commissioned a heat pump before applying. The installer must be MCS-certified and the work must be completed within 12 weeks of approval.
You are still eligible as long as the recommendation is for solid-wall insulation, the condition only blocks applications with unfilled cavity-wall or loft-insulation recommendations. However, a solid-wall-insulation recommendation may lower your EPC score, so check your certificate carefully before applying.
