Great British Insulation Scheme (GBIS): Warm homes plan funding

The Great British Insulation Scheme, the route most people are told they do not qualify for

The Great British Insulation Scheme, or GBIS, is the part of the Warm Homes Plan funding landscape that the most eligible households wrongly rule themselves out of. The common assumption is that home energy grants are only for people on benefits. That is not true of GBIS. It funds a single insulation measure, loft, cavity wall, solid wall, room-in-roof or underfloor, and it has two separate eligibility routes. The first is a Low-Income Group, on the same means-tested benefits as ECO4. The second, and the one most often missed, is a broader General Group, open to homes in Council Tax bands A to D in England, or A to E in Scotland and Wales, with an EPC of D or below. No benefit is required for the General Group. If your home is in a lower Council Tax band and has a poor EPC, you may well qualify for funded insulation even on a full working income.

This sits squarely inside the Warm Homes Plan because GBIS is one of the legacy schemes being wound down as the plan takes over. It is delivered by six obligated suppliers, British Gas, EDF, E.ON, OVO, Scottish Power and Octopus Energy, and it closes to new measures on 31 March 2026. After that, insulation funding continues through the Warm Homes Plan routes, including the council-delivered Warm Homes: Local Grant. The practical message is that GBIS is a live, time-limited route to a funded insulation measure, and the General Group makes it far more widely available than competitors tend to admit.

What a typical GBIS measure looks like and how eligibility is assessed

GBIS funds one measure rather than a whole-house package, so the assessment is about which single insulation measure your home needs and which eligibility group you fall into, not a kilowatt sizing. The General Group test is the one to know, Council Tax bands A to D in England (A to E in Scotland and Wales) with an EPC of D or below, no benefit needed. The Low-Income Group uses the same means-tested benefits as ECO4 and is open to any Council Tax band. Once eligibility is confirmed, the funded measure is typically loft, cavity wall, solid wall, room-in-roof or underfloor insulation, chosen for the property. The value is a single insulation measure, largely or fully funded depending on the group and the measure, with at most a low contribution from the household.

Because it is a single measure, GBIS is often the right route for a household that does not need a full retrofit but does have one obvious weakness, an uninsulated loft, an empty cavity, a cold room in the roof. We confirm the Council Tax band and EPC, identify the measure, and route the application through your supplier, the gov.uk checker or a TrustMark installer.

Tenure does not shut you out of GBIS either. The scheme is available to tenants as well as owner-occupiers, with the landlord's permission for the work, since insulation is a physical improvement to the building. For a private renter that can be a straightforward conversation, particularly because landlords already cannot let the worst-rated properties under Minimum Energy Efficiency Standards, so funded insulation that lifts the rating helps the landlord meet their own obligations. The six obligated suppliers that deliver GBIS, British Gas, EDF, E.ON, OVO, Scottish Power and Octopus Energy, will each run their own eligibility checks, and you do not have to be a customer of a particular supplier to be assessed, which widens the route further.

Costs, what you pay, and tax relief

For most eligible homes GBIS is free or close to it. The funded measure is largely or fully funded, with at most a low contribution depending on the group and the insulation type, so there is no investment payback to calculate, the value is the reduced heat loss and warmer home from day one. Insulation is among the most cost-effective measures there is, loft and cavity-wall insulation cut heat loss immediately, which is why a single funded measure can make a real difference to bills. There is no repayment because GBIS is a grant, not a loan, and the Annual Investment Allowance and Smart Export Guarantee are commercial mechanisms that do not apply to this domestic insulation route. Our cost guide sets out what, if anything, a household contributes by group and measure.

The level of funding can vary with the measure and the group, which is worth understanding before you commit. Lower-cost measures such as a loft insulation top-up are often fully funded, while a more involved measure such as solid wall or room-in-roof insulation can carry a small household contribution depending on the group you qualify under. The Low-Income Group, on means-tested benefits, generally attracts the most generous funding, while the General Group, routed by Council Tax band, may involve a modest contribution on some measures. We tell you which group you fall into and what, if anything, you would pay before any work is agreed, so there is no surprise on the final invoice. Either way, the contribution is a fraction of the full cost, and the warmer, cheaper-to-run home is the lasting benefit.

Funding routes in detail

GBIS is the single-measure route, but it often pairs with others. A household that qualifies for GBIS insulation and also wants a heat pump can use the Boiler Upgrade Scheme separately for the heating, since BUS is open to any homeowner in England or Wales replacing a fossil-fuel system regardless of income. A household that needs more than one measure, or a full retrofit, may be better served by ECO4 if it is on a qualifying benefit, or by the council-delivered Warm Homes: Local Grant on an income route. Because GBIS closes to new measures on 31 March 2026, and ECO4 to applications on the same date, the timing of any combined approach matters. You can read the scheme rules on the Ofgem Great British Insulation Scheme page.

Sequencing the fabric work first is the smart play if you are combining routes. Insulating under GBIS before a heat pump goes in under the Boiler Upgrade Scheme means the heat pump is sized for a warmer, less leaky home and runs more efficiently from day one. This is the same fabric-first logic that governs the whole-house ECO4 route, and it is the reason a single GBIS measure can be valuable even when a heat pump is also on the cards. After GBIS closes to new measures in March 2026, insulation funding continues under the Warm Homes Plan, including through the council-delivered Warm Homes: Local Grant, so a household that misses the GBIS window still has a successor route, though the eligibility tests differ.

Compliance and sector considerations

Insulation under GBIS is installed to PAS 2030 and PAS 2035 standards and lodged with TrustMark, so a funded measure comes with the documented assessment and guarantee that protects you if anything goes wrong. The headline compliance point is the deadline, GBIS closes to new measures on 31 March 2026, so an eligible household needs the measure applied for and lodged before that date. Most insulation is Permitted Development, but external solid wall insulation can need planning permission in a conservation area, and listed buildings need Listed Building Consent for external changes, which a PAS 2035 retrofit assessor will flag before work starts. Applications go through one of the six obligated suppliers, the gov.uk eligibility checker, or a TrustMark-registered installer.

How we approach this kind of project

We lead with the General Group, because it is the route most sites bury or omit, and it is the reason a working household with no benefits can still get funded insulation. We check your Council Tax band and EPC first, tell you honestly which group you fall into, and route the application through a TrustMark-registered installer or an obligated supplier rather than a doorstep caller. We work to the 31 March 2026 closing date, treating eligible enquiries as time-sensitive, and we make clear which single measure the scheme will fund so there are no surprises. We also point you to the official gov.uk checker so you can confirm eligibility for yourself.

We are realistic about what a single insulation measure will and will not do, because honesty is the point of this hub. Loft and cavity-wall insulation are among the most cost-effective measures available and cut heat loss straight away, so a funded GBIS measure usually pays back in comfort and lower bills from the first winter. We will tell you where a single measure is enough on its own and where it is really the first step of a larger job that other routes should fund. Because the work is lodged with TrustMark and installed to PAS 2030 and PAS 2035 standards, you get a documented, guaranteed measure with a clear route to redress, not an unrecorded cash job. As with every route, we never cold-call, never ask for a deposit, and always recommend you verify the installer's TrustMark registration before agreeing to anything, since a legitimate GBIS measure is funded through the scheme and not paid for up front by the household.

An illustrative example

As an illustrative composite based on a typical GBIS General Group route, consider a 1930s mid-terrace, owner-occupied, in EPC band D and Council Tax band C, where the household is not on any benefits but struggles with an uninsulated loft and cold upstairs rooms. Under the GBIS General Group, that home could qualify on Council Tax band and EPC alone, with no benefit needed, and receive a funded loft insulation top-up to current standard as a single measure, installed by a TrustMark-registered installer and lodged before the 31 March 2026 closing date. The case illustrates the central point, that being off benefits does not mean no funding. The figures and outcome are illustrative and depend on your property, your eligibility group and the live scheme rules.

Not on benefits but in a low Council Tax band? You may still qualify. Read the grants and funding guide, check the detail on the cost page, then tell us about your home before GBIS closes. You can also read the funding FAQs, or compare GBIS with the fully funded ECO4 route and the council-delivered Warm Homes: Local Grant.