The Great British Insulation Scheme is the most accessible of the UK’s energy grant programmes — its ‘general group’ eligibility opens insulation funding to working households who would not qualify for ECO4. If your home has an EPC rating of D or below and is in a lower council tax band, you may qualify without any means-testing.
For a full overview of energy grants, see the Grants and Schemes hub.
GBIS vs ECO4 — Key Differences
| GBIS | ECO4 | |
|---|---|---|
| EPC requirement | D or below | D–G (whole-house approach) |
| Benefit requirement | Low income group only | Yes (or LA Flex) |
| General eligibility | Yes (council tax band A–D, EPC D or below) | No general group |
| Measures covered | Single insulation measure | Multiple measures, heat pumps |
| Whole-house approach | No — one measure per property | Yes |
| Heat pumps included | No | Yes |
| Typical cost to household | Free to low/nil contribution | Free |
Who Qualifies — General Group
No means-test is required. You need:
- Property in council tax band A–D (England), A–E (Scotland), A–C (Wales)
- An EPC rating of D, E, F, or G
- Property must be a residential home (not commercial)
The council tax band restriction is key — households in higher-value properties (bands E–H) must use the low income group route.
Who Qualifies — Low Income Group
Receipt of any of the following:
- Universal Credit
- Pension Credit
- Income-based JSA or ESA
- Child Tax Credit or Working Tax Credit (household income under £31,000)
- Housing Benefit
- Income Support
No council tax band restriction applies for the low income group.
What Is Covered
GBIS funds the single most impactful insulation measure for a specific property, determined by a surveyor:
| Measure | Typical annual bill saving |
|---|---|
| Loft insulation (uninsulated to 270mm) | £150–£300 |
| Loft insulation top-up (thin to 270mm) | £50–£150 |
| Cavity wall insulation | £200–£400 |
| Solid wall insulation (external) | £400–£800 |
| Solid wall insulation (internal) | £350–£700 |
| Underfloor insulation (suspended floors) | £100–£200 |
| Room-in-roof insulation | £200–£500 |
| Park home insulation | £400–£700 |
Savings are approximate for a medium-sized home at current energy prices and vary based on property size, location, and heating system.
Typical Grant Values Under GBIS
GBIS does not publish a fixed per-household cap, but indicative values based on scheme guidance:
| Measure | Approximate grant value |
|---|---|
| Cavity wall insulation | £400–£1,500 |
| Loft insulation (new) | £700–£1,500 |
| Loft insulation (top-up) | £300–£700 |
| Solid wall insulation (external) | £5,000–£15,000 |
| Solid wall insulation (internal) | £4,000–£12,000 |
| Room-in-roof insulation | £3,000–£7,000 |
| Park home insulation | £5,000–£10,000 |
Grant amounts vary by installer, property type, and delivery partner. For the general group, the household may need to contribute the gap between the grant value and the full installation cost — particularly for solid wall insulation.
Worked Example — Semi-Detached With Cavity Walls (General Group)
Household profile: Semi-detached 1970s house, gas heating, EPC D, two adults working, combined income £45,000. Not on benefits. Council tax band C.
- Qualifies via General Group (council tax band C, EPC D — both criteria met)
- Surveyor visits and confirms unfilled cavity walls
- Cavity wall insulation installed at no cost under GBIS
- Estimated annual saving: £180–£320 on heating bills
An otherwise identical household with EPC B or C would not qualify through the General Group (EPC must be D or below). They would need to be on a qualifying benefit for the Low Income Group route.
Worked Example — Pensioner With Solid Walls (Low Income Group)
Household profile: Terraced Victorian house, gas central heating, EPC E. Household on Pension Credit.
- Qualifies via Low Income Group (Pension Credit, EPC E)
- Surveyor identifies external solid wall insulation as the primary measure
- Solid wall insulation installed — cost to household: nil (fully funded)
- Estimated annual saving: £400–£700 on heating
What Happens During the Assessment
An approved GBIS installer visits your property to:
- Confirm the property meets EPC and council tax criteria
- Assess what insulation measure would be most effective
- Check that existing insulation is not already at the recommended standard
- Quote the cost and identify the grant amount
The installer submits your case to Ofgem’s system. If approved, work is usually scheduled within a few weeks.
How to Apply
- Contact your energy supplier — all large suppliers participate in GBIS; some smaller ones also
- Use the Simple Energy Advice service at simpleenergyadvice.org.uk
- Contact an approved GBIS installer directly — search TrustMark or the Ofgem GBIS installer database
- An assessment is arranged — a surveyor visits to determine what measure is suitable
- Work is carried out — often within weeks of application
Getting multiple quotes: For more expensive measures (solid wall insulation), it is worth contacting more than one GBIS installer, as grant values and any household contribution can vary.
Common Issues and How to Handle Them
Installer says you need to contribute: For the general group, a contribution toward solid wall insulation is sometimes required. Confirm the grant amount in writing before agreeing to any payment.
Declined because EPC is too high: An EPC of C or above excludes you from GBIS. If you believe your EPC is inaccurate (e.g. it was done years ago and doesn’t reflect current property features), you can commission a new EPC (cost: £60–£120) before applying.
No installers available in your area: GBIS delivery varies by region. If local installer capacity is limited, contact your energy supplier directly — they may have their own delivery routes.
Work completed but substandard: All GBIS installers must hold TrustMark accreditation. For complaints, use the TrustMark dispute resolution service.
After Installation
Following GBIS insulation work:
- Your EPC is updated — you may move from band D to C, or E to D (or better)
- This improvement can affect your mortgage options (some lenders offer better rates for EPC C+ properties)
- If you are a landlord, an improved EPC may help you meet the Minimum Energy Efficiency Standards
- Your energy bills should fall in the next heating season — keep bills from before and after to compare