The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. The scheme is managed by Ofgem and typically covers up to 100% of the cost for qualifying applicants (GOV.UK, 2026).
- Check your EPC rating on the GOV.UK find an energy certificate service.
- Apply through a TrustMark registered installer, not directly to the government.
- Households with an EPC rating of D or below are likely eligible.
The grant is not available to everyone. Eligibility depends on your property’s Energy Performance Certificate (EPC) rating, your household income, and whether you receive certain benefits. If your home has an EPC rating of D or below and you own or privately rent the property, you are likely eligible. Homeowners, private tenants and landlords can apply, but social housing tenants should check with their landlord first.
Check your eligibility first
Before applying, confirm your household qualifies. You must live in England, Scotland or Wales, and your property must have an EPC rating of D, E, F or G with no existing insulation in the target area. Households receiving means-tested benefits such as Universal Credit, Pension Credit or Income Support are automatically eligible. Those with an annual household income under £31,000 may also qualify (Ofgem, 2026). You can check your EPC rating on the GOV.UK find an energy certificate service.
Apply through a certified installer
You cannot apply directly to the government. Instead, find a TrustMark registered installer who is authorised to deliver the Great British Insulation Scheme. TrustMark is the government-endorsed quality scheme. The installer will assess your home, confirm eligibility and handle the grant application on your behalf. The grant covers the full cost of installation for most standard measures, though some households may need to contribute a small amount if the work exceeds the grant cap (TrustMark, 2026).
Choose the right insulation type
The grant covers cavity wall insulation, loft insulation, solid wall insulation (internal or external), flat roof insulation and underfloor insulation. The installer will recommend the most cost-effective option based on your property. Loft insulation is typically the quickest and cheapest to install, while solid wall insulation costs more but delivers greater energy savings. Energy Saving Trust says a detached home with cavity wall insulation can save around £345 per year on heating bills (Energy Saving Trust, 2026). The installer will provide a full quote before work begins, and you should not pay any upfront fees unless agreed.
A worked example
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. The householder, who receives Pension Credit, qualifies automatically under the low-income route and pays nothing upfront because the TrustMark registered installer claims the grant directly from Ofgem. With the 0% VAT rate on energy-saving materials running until March 2027, the total installer cost of £2,800 is fully covered by the scheme. Over 25 years the total savings reach £9,625, making this one of the most cost-effective upgrades a household can make. The work takes two days and the installer arranges a post-installation inspection to meet MCS certification standards.
| Item | Figure |
|---|---|
| Upfront cost after grants | £0 |
| Yearly savings | £385 |
| Payback period | Immediate |
| 25-year lifetime savings | £9,625 |
What homeowners often get wrong
The most common mistake is assuming you apply directly to the government for the grant. You must find a TrustMark registered installer who handles the application on your behalf. Here are three frequent errors that cost homeowners time and money.
- Applying before checking your EPC rating You might think you qualify based on your income alone, but the scheme requires an EPC rating of D or below. Without checking first, you waste weeks waiting for a rejection that could have been avoided with a 10-minute look at the GOV.UK find an energy certificate service.
- Choosing an unregistered installer Some companies claim they are “accredited” but are not on the TrustMark or MCS registers. Using them voids the grant entirely and leaves you paying the full £2,800 yourself with no recourse. Always verify the installer on the TrustMark website before any work starts.
- The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. Missing this distinction means you could leave thousands of pounds in additional grants unclaimed. Check both schemes on the Ofgem website before you book.
Quick reference
- The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
- You must have an EPC rating of D, E, F, or G with no existing insulation in the target area to qualify.
- Households receiving Universal Credit, Pension Credit, or Income Support are automatically eligible under the low-income route.
- Annual savings from loft and cavity wall insulation typically range from £200 to £600 depending on your property size and fuel type.
- Only TrustMark registered installers can claim the grant, and you must use them to avoid paying the full cost yourself.
Frequently Asked Questions
Check your property's EPC rating on the GOV.UK find an energy certificate service. Households with an EPC rating of D or below, receiving means-tested benefits or with an annual income under £31,000, are eligible according to Ofgem.
You must find a TrustMark registered installer who is authorised to deliver the Great British Insulation Scheme.
The grant typically covers up to 100% of the cost for qualifying applicants, as confirmed by GOV.UK. This includes free or heavily subsidised cavity wall, loft and solid wall insulation.
