Great British Insulation Scheme and ECO4: Complete Guide to Free Insulation Grants in 2025
Here's a fact that might surprise you: the average UK home loses around 35% of its heat through the walls and 25% through the roof. That's energy you've paid for, escaping into the atmosphere. It's money literally evaporating through your brickwork.
The good news? Two major government schemes—the Great British Insulation Scheme (GBIS) and ECO4—are helping homeowners plug these gaps at little or no cost. Between them, they've funded insulation improvements in over 500,000 homes since 2022.
But navigating these schemes can feel confusing. Eligibility criteria differ. Available measures vary by property type. And the application process isn't always intuitive.
This guide cuts through the complexity. We'll explain who qualifies, what's covered, and how to access the funding you're entitled to.
The Two Main Schemes: An Overview
Great British Insulation Scheme (GBIS)
Launched in March 2023, GBIS specifically targets insulation improvements in less energy-efficient homes. It's designed to be accessible to middle-income households who don't qualify for means-tested benefits but still struggle with energy costs.
Key features:
- Available to homes with EPC ratings D, E, F, or G
- Council tax bands A-D in England (A-E in Scotland and Wales)
- No need to receive benefits—though benefit recipients can access additional support
- Covers cavity wall insulation, loft insulation, solid wall insulation, flat roof insulation, and room-in-roof insulation
- Runs until March 2026
ECO4 (Energy Company Obligation)
ECO4 is the fourth iteration of the Energy Company Obligation scheme, running from April 2022 to March 2026. Unlike GBIS, ECO4 primarily targets low-income and vulnerable households.
Key features:
- Available to households receiving qualifying benefits
- Also accessible via local authority "flexible eligibility" for households identified as fuel-poor
- Covers a broader range of measures including insulation, heating upgrades, and solar panels
- Requires properties to have an EPC rating of D, E, F, or G (though this can be relaxed in some circumstances)
Who Qualifies for GBIS?
GBIS eligibility is based on your property and location rather than your income:
Standard Eligibility
- EPC rating: Your home must be rated D, E, F, or G on its Energy Performance Certificate
- Council tax band: Bands A-D in England (A-E in Scotland and Wales)
- Property type: Houses, bungalows, and flats all qualify. Private and social housing both eligible.
Enhanced Eligibility (Receiving Benefits)
If you receive qualifying benefits, the council tax band restriction doesn't apply. Any EPC D-G property qualifies regardless of band.
Qualifying benefits include:
- Universal Credit
- Pension Credit (Guarantee Credit)
- Income Support
- Income-based Jobseeker's Allowance
- Income-related Employment and Support Allowance
- Child Tax Credit (income under £16,480)
- Working Tax Credit (income under £16,480)
- Housing Benefit
What GBIS Covers
GBIS focuses specifically on insulation. Available measures include:
- Cavity wall insulation: For homes with unfilled cavity walls (typically built 1930s-1990s)
- Loft insulation: Top-up or full installation to current standards (300mm)
- Solid wall insulation: Internal or external—though this is more expensive and less commonly funded
- Flat roof insulation: For properties with flat roofs over heated spaces
- Room-in-roof insulation: For converted loft spaces used as rooms
Who Qualifies for ECO4?
ECO4 has more restrictive eligibility but offers a broader range of measures:
Standard Eligibility
- Benefits requirement: You must receive one of the qualifying benefits listed above
- EPC rating: Generally D, E, F, or G—though there's flexibility in some circumstances
- Property ownership: Both homeowners and private tenants can qualify (landlord permission needed for tenants)
Flexible Eligibility
Even without qualifying benefits, you may access ECO4 if your local authority identifies you as fuel-poor or vulnerable to the effects of living in a cold home.
Councils can refer households based on factors like:
- Low income relative to energy costs
- Health conditions exacerbated by cold housing
- Living in an area with high fuel poverty rates
Contact your local council's housing or environment team to ask about flexible eligibility in your area.
What ECO4 Covers
ECO4 covers insulation and more:
- All the insulation measures available under GBIS
- Heating system replacements: Including heat pumps, efficient boilers, and storage heaters
- Solar panels: In some cases, as part of a package of measures
- Heating controls: Smart thermostats and heating control upgrades
What Does Free Really Mean?
Under both schemes, the funding comes from energy suppliers obligated to improve household energy efficiency. For most eligible households, the measures are genuinely free—you pay nothing.
However, some scenarios involve contributions:
- Solid wall insulation: Due to high costs (£10,000-£20,000+), you may be asked for a contribution even under full funding schemes. Some installers absorb this; others don't.
- Non-standard properties: Unusual constructions or access difficulties can increase costs beyond what funding covers.
- Income above thresholds: Under flexible eligibility, councils sometimes offer partial rather than full funding.
Always confirm in writing what you'll pay (if anything) before work begins. Reputable installers provide clear quotes showing any homeowner contribution.
Real Homeowner Experiences
Janet, Leeds (1950s semi, cavity wall insulation): "Our walls were hollow—we could literally feel the cold coming through in winter. I found out about GBIS through a leaflet that came through the door. Checked our eligibility online, filled in some details, and a surveyor came round within two weeks. The actual insulation took about three hours. They drilled small holes in the outer wall, pumped in the insulation, filled the holes, and left. Our heating bills dropped noticeably that first winter—I'd estimate 15-20% less gas use. Completely free. Still can't quite believe it."
Mohammed, Birmingham (Victorian terrace, loft insulation top-up): "Our loft had old insulation from when we bought the place—maybe 100mm, quite compressed. Under ECO4, they came and topped it up to 300mm. Also sealed around the loft hatch properly and lagged the pipes up there. The bedroom below the loft used to be noticeably colder than other rooms. Not anymore. They left a slight mess in the loft itself but nothing we couldn't live with. The whole thing was done in a morning."
Carol, Newcastle (1930s end terrace, multiple measures): "I'm on Pension Credit so qualified for ECO4. We had cavity wall insulation, loft insulation, and they replaced our ancient boiler with a new efficient one. All free. The house feels completely different now. I used to dread winter—wearing extra jumpers indoors, only heating one room. Now the whole house stays warm on half the gas we used before. It's genuinely changed my life. I tell everyone who'll listen to apply."
Steve and Lucy, Bristol (1970s house, solid wall insulation): "We have solid walls so cavity insulation wasn't an option. Applied through GBIS but were told there'd be a contribution needed for external wall insulation—around £2,500. We went ahead anyway because the funding still covered about £12,000 of the cost. The house looks different now with the new render, but the difference in warmth is remarkable. Our energy bills are down about 40%. The contribution paid for itself in saved heating costs within two winters."
How to Apply
The application process for both schemes follows a similar pattern:
- Check your EPC: Find it at gov.uk/find-energy-certificate. You need a D, E, F, or G rating.
- Confirm eligibility: Use the Simple Energy Advice website or contact an approved installer directly.
- Survey booking: An assessor visits your home to confirm what measures are suitable and what funding applies.
- Quote and acceptance: You receive a written proposal showing measures, funding, and any contribution required.
- Installation: Work is scheduled at a convenient time. Duration varies from a few hours (loft insulation) to several days (solid wall insulation).
- Sign-off: Once complete, you receive documentation confirming the work done.
Beware of cold-callers or pressure sales tactics. While many legitimate installers do proactive outreach, never sign anything on the doorstep. Take time to verify credentials and compare quotes if possible.
Common Questions
Do I need to own my home?
Not necessarily. Private tenants can access both schemes with landlord permission. Social housing tenants should ask their housing association or council about energy efficiency programmes—many run their own in addition to national schemes.
Will it damage my home?
Properly installed insulation shouldn't cause problems. However, cavity wall insulation in exposed or already-damp properties can potentially trap moisture. A good surveyor will identify unsuitable properties and recommend alternative measures.
How long does it take?
From application to installation typically takes 2-8 weeks depending on installer availability and measure complexity. Loft insulation can often be scheduled within days. Solid wall insulation takes longer to survey, quote, and install.
What if I've already had work done?
You can still qualify for measures you haven't had. If your loft is already insulated but your walls aren't, you can get cavity wall insulation through the schemes. Previous measures don't disqualify you from additional ones.
The Impact of Insulation
The financial and comfort benefits of insulation are substantial:
| Measure | Typical Annual Saving | Carbon Reduction |
|---|---|---|
| Cavity wall insulation | £295 | 560 kg CO2 |
| Loft insulation (0 to 270mm) | £355 | 670 kg CO2 |
| Solid wall insulation (internal) | £455 | 870 kg CO2 |
| Solid wall insulation (external) | £490 | 930 kg CO2 |
(Figures from Energy Saving Trust based on typical gas-heated semi-detached house)
Beyond direct savings, insulated homes are more comfortable, with fewer cold spots and draughts. They stay cooler in summer heat. They're healthier—reduced damp and mould improve respiratory conditions. And they're more valuable—better EPC ratings translate to higher property values.
Taking Action
Millions of UK homes remain poorly insulated. If yours is one of them, these schemes offer a practical route to improvement—often at no cost whatsoever.
Start by checking your EPC. If you're D-rated or below, you're likely eligible for help. Even if you're C-rated, specific measures might qualify under certain circumstances.
The schemes run until 2026, but funding is allocated on a first-come basis. Installers are busy. Acting sooner means getting the benefits sooner—and reduces the risk of missing out if programmes are fully subscribed.
Cold homes are expensive homes. They're uncomfortable homes. And increasingly, they're hard-to-sell homes as EPC requirements tighten. Insulation addresses all three concerns simultaneously.
If you qualify, there's genuinely no reason not to apply. The process is straightforward. The work is minimally disruptive. And the benefits last for decades.
Check your eligibility today. Your warmer, cheaper, more comfortable home awaits.