How to Stack Cornwall Energy Grants: BUS, ECO4, HEAT and VAT Relief in 2026

The grants available in 2026

Cornwall homeowners in 2026 can access at least four distinct grant or relief mechanisms for home energy upgrades. Understanding which can be stacked — and in what order to apply — can save thousands of pounds. The four mechanisms are:

• Boiler Upgrade Scheme (BUS) — £7,500 towards a heat pump, applied directly against the installer's quote.
• ECO4 / Great British Insulation Scheme (GBIS) — Free or subsidised insulation and heating for eligible lower-income households.
• HEAT Cornwall — Cornwall Council's own scheme providing free or subsidised renewable energy measures for households earning under £30,000.
• 0% VAT on energy-saving materials — Zero VAT rate on solar panels, batteries, heat pumps, insulation and installation labour until March 2027.

BUS grant: rules and eligible works

The Boiler Upgrade Scheme provides £7,500 towards an air source heat pump installation. Key rules:

• You must be replacing an existing fossil fuel heating system (gas, oil, LPG, or electric storage).
• You must have a valid EPC (Energy Performance Certificate) dated in the last ten years.
• Any outstanding EPC recommendations for loft or cavity wall insulation must be addressed first — or you can get a written exemption if the measures are technically unsuitable.
• Only MCS certified installers can apply for the grant — we handle the application on your behalf.
• The £7,500 is deducted directly from your invoice. You never see the money; we claim it from Ofgem after installation.

ECO4 and Great British Insulation Scheme

ECO4 is funded by energy suppliers and administered by Ofgem. It provides free insulation (loft, cavity, solid wall) and heating upgrades for eligible households — typically owner-occupiers or private renters on specific benefits or with household incomes under £31,000. The scheme covers Cornwall and can fund measures including heat pumps, solar, and insulation, depending on property EPC band and household eligibility.

The Great British Insulation Scheme targets homes in EPC D–G bands and can fund loft insulation, cavity wall insulation, and solid wall insulation. Both schemes are administered through energy suppliers; we can assess your eligibility during a survey visit.

HEAT Cornwall scheme

HEAT Cornwall is Cornwall Council's own programme providing free or heavily subsidised renewable energy measures — solar panels, heat pumps, and insulation — for eligible Cornwall residents. Eligibility is primarily income-based (under £30,000 household income) and is targeted at specific deprived areas across the county, including parts of Truro, Camborne, Redruth, St Austell, and Penzance. Applications can be made directly through Cornwall Council, and we assist eligible customers during the survey visit.

0% VAT on energy-saving materials

Since April 2022, energy-saving materials — including solar panels, batteries, heat pumps, heat pump hot water cylinders, draught stripping, insulation, and associated installation labour — are zero-rated for VAT purposes. This applies to residential properties and remains in place until March 2027. On a £14,000 heat pump installation, the 0% rate saves £2,333 compared to standard-rated 20% VAT. On a £7,000 solar installation it saves £1,167. This is automatically applied to every eligible invoice we raise — there is nothing to claim.

Which grants can be combined

The good news: most of these mechanisms can be stacked. The 0% VAT applies to all qualifying works regardless of which other grants you receive — it is not means-tested or a grant at all. The BUS grant stacks with 0% VAT (we apply 0% VAT to the gross cost before deducting the BUS grant, so you get both). ECO4 and HEAT Cornwall cannot be used on the same measure at the same time, but ECO4 can fund insulation while HEAT Cornwall funds the heat pump — or vice versa depending on which scheme has capacity.

A worked example: A Cornwall homeowner on ECO4 benefits gets free loft and cavity insulation through ECO4 (say £3,000 value). Then installs a heat pump with the BUS grant (saves £7,500) at 0% VAT (saves £2,300). Total support received: £12,800 against an otherwise £21,800 project.

Optimal stacking strategy

For maximum benefit, the sequence is: (1) check ECO4/GBIS eligibility for insulation first — these have no interaction with the BUS grant and make your heat pump more efficient; (2) apply for BUS through your MCS installer; (3) note the 0% VAT is automatic; (4) if you are in a HEAT Cornwall target area and income-eligible, contact Cornwall Council to check whether additional support is available.

We carry out a full grant eligibility check during every free survey. Book your survey or see our full grants and funding guide.