The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. In 2026, the maximum grant per measure is £1,600 for cavity-wall insulation and £1,600 for loft insulation, though most households receive a lower amount depending on property size and the type of insulation installed (DESNZ, 2026). The scheme is funded by energy suppliers under the Energy Company Obligation (ECO) framework and administered by Ofgem.
The actual grant you receive is calculated based on the number of walls or loft area being insulated, not a flat rate. For a typical three-bedroom semi-detached house, cavity-wall insulation costs around £800–£1,200 to install, and loft insulation (top-up from 60mm to 270mm) costs roughly £500–£900. The grant covers the full installation cost up to the £1,600 cap per measure, so many households pay nothing at all (Ofgem, 2026).
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. There are two routes to qualify.
The income-based route is open to households with a total annual income below £31,000, or below £36,000 if you live in certain postcodes in London and the South East. The benefits-tested route covers anyone receiving Universal Credit, Pension Credit, Child Tax Credit, Working Tax Credit, Income Support, income-based Jobseeker’s Allowance, or income-related Employment and Support Allowance (Ofgem, 2026).
The property must be owned or privately rented (with landlord consent). The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
Quick numbers – key GBIS figures for 2026
| Measure | Grant cap | Typical annual saving | Installation time | U-value improvement |
|---|---|---|---|---|
| Cavity-wall insulation | £600–£1,600 | £160–£240 | 1–2 hours | Pre ~1.5 W/m²K, post ~0.3 W/m²K |
| Loft insulation (top-up to 270mm) | £400–£1,600 | £180–£285 | 2–4 hours | Pre ~0.5 W/m²K, post ~0.16 W/m²K |
Savings figures are based on a typical gas-heated three-bedroom semi-detached home in England, Scotland, and Wales (Energy Saving Trust, 2026). U-value improvements show how much less heat escapes after installation (EST U-value calculator, 2026). Actual savings depend on your property size, heating system, and energy tariff.
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. Here is the step-by-step process.
Step 1: Check eligibility. Use the GOV.UK eligibility checker at gov.uk/great-british-insulation-scheme. You will need your postcode, property type, and current insulation status (GOV.UK, 2026).
Step 2: Find an approved installer. Only use MCS-certified installers listed on the Ofgem-approved register. Do not use unregistered traders, as the funding cannot be claimed without proper certification (Ofgem, 2026).
Step 3: Free survey. The installer visits your home to assess cavity-wall suitability, loft access, and existing insulation depth. They measure the area and check for any damp or structural issues.
Step 4: Installer applies for funding. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. Approval typically takes 2–4 weeks (GOV.UK, 2026).
Step 5: Installation and completion. The work is completed in one day for both measures. The installer submits completion paperwork to Ofgem, and you should receive a certificate of installation.
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. ECO4 can fund multiple measures in the same home, such as cavity-wall insulation plus a heat pump. Both schemes require an EPC rating of D, E, F, or G, but ECO4 also has a low-income priority group that can access more generous funding (DESNZ, 2026).
A key difference is property value. GBIS has no cap on property value. ECO4 is limited to properties with a council tax band A–D in England and A–E in Scotland and Wales (Ofgem, 2026).
Compare ECO4 eligibility with GBIS side by side
How to verify a GBIS installer – MCS certification and TrustMark registration
All GBIS installations must be carried out by an installer certified under the Microgeneration Certification Scheme (MCS) for cavity-wall and loft insulation. You can check the MCS public register at mcscertified.com (MCS, 2026).
Installers must also hold TrustMark registration, a government-endorsed quality scheme that covers consumer protection and workmanship standards. Verify registration at trustmark.org.uk (TrustMark, 2026).
If the installer bundles any gas-safe work (such as boiler upgrades under ECO4), they must be registered with the Gas Safe Register. For any electrical work, they need NICEIC or NAPIT registration (Gas Safe Register, 2026).
How to check if an insulation installer is legit
The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
No. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. Solid-wall insulation, whether internal or external, is not covered under this scheme (Ofgem, 2026).
If your home has solid walls (typically pre-1930s properties), you must apply for solid-wall insulation through ECO4 if you are eligible, or pay privately. The Home Energy Scotland Grant and Loan also offers funding for solid-wall insulation in Scotland (DESNZ, 2026). Expect solid-wall insulation to cost between £8,000 and £22,000 depending on property size and whether you choose internal or external insulation.
Frequently Asked Questions
Up to £1,600 per measure for cavity-wall or loft insulation. The actual amount depends on the size of your property and the type of insulation installed, according to DESNZ and Ofgem.
You must either have an income below £31,000 (£36,000 in some areas) or receive qualifying benefits, per GOV.UK.
Yes, for many households. The grant covers the full installation cost up to the £1,600 cap per measure, so you pay nothing if the work costs less than that, according to Ofgem.
Yes, cavity-wall insulation is a core measure under GBIS. The maximum grant is £1,600, and typical installation for a 3-bed semi costs £800-£1,200, per DESNZ.
The grant is up to £1,600, and typical costs for a 3-bed semi are £500-£900, per Ofgem.
