The Great British Insulation Scheme, usually shortened to GBIS, was a government-backed programme that helped millions of households in England, Scotland and Wales fit insulation at little or no cost. It ran from 2023 until the spring of 2026, when its referral service closed. Even though you can no longer apply, the scheme is worth understanding: it sets the pattern for the help that is replacing it, and the measures it funded are still the cheapest, highest-value upgrades you can make to a cold home.
The short answer. GBIS was an Ofgem-administered scheme that obliged larger energy suppliers to fit insulation in poorly rated homes. There were two routes in: a low-income group (means-tested benefits or household income under £31,000), who paid nothing, and a wider general group (EPC band D to G, in lower council tax bands), who got a heavily subsidised single measure such as cavity wall or loft insulation. The referral service closed at the end of March 2026, and the Warm Homes Plan now carries the work forward.
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What the scheme was and why it existed
GBIS was funded the same way most British energy-efficiency help is funded: not from a pot of cash you apply to directly, but through an obligation placed on energy suppliers. Any supplier with 150,000 or more domestic customers had to deliver a set amount of insulation across the country, and the cost was spread across everyone's bills. Ofgem ran the scheme and checked that the work was done properly.
The aim was simple. Around a third of the heat in a typical uninsulated home escapes through the walls and roof, so insulating them is the most reliable way to cut a gas bill. By targeting the worst-rated properties, the scheme tried to take the coldest, most expensive homes and make them cheaper to heat. If you want the bigger picture on how heat and money leak out of a house, our guide to understanding your energy bill breaks down where the cost actually goes.
GBIS sat alongside ECO4, a separate and more generous scheme aimed squarely at low-income households. The two often got confused. ECO4 funds deeper, whole-house retrofits; GBIS was lighter touch and reached a far wider group of homeowners and tenants. Our ECO4 scheme guide covers that other route in full.
Who qualified: the two groups
There were two ways into the scheme, and which one you fell into decided whether you paid anything at all.
The low-income group
This route was for households on a means-tested benefit, or with a total gross household income below £31,000 a year. If you qualified here, the work was fully funded and you paid nothing towards it. There was no council tax band restriction for this group.
The general group
This was the wider route, open to people regardless of income, and it is what made GBIS unusual. To qualify, your home needed:
- An Energy Performance Certificate rating of D, E, F or G. You can check yours through our guide to the EPC explained.
- A council tax band of A to D in England, or A to E in Scotland and Wales.
The general group usually paid a contribution towards the work rather than getting it free, but the subsidy was large enough that fitting insulation became affordable for households who would never otherwise have done it. Both owner-occupiers and private tenants could take part, though tenants needed the landlord's consent.
What it actually paid for
The scheme funded one main insulation measure per home, chosen by a retrofit assessment of your property. The assessor looked at where your home lost the most heat and what would cut energy use most cost-effectively. In practice the work clustered around a handful of measures.
Cavity wall insulation was the single most common measure, making up well over a third of all installations, followed by loft insulation. Other measures included solid wall insulation, room-in-roof insulation, underfloor insulation and flat-roof insulation. From mid-2025, loft insulation could be added as a secondary measure, so some homes received both cavity wall and loft insulation together.
The table below shows the typical annual saving from the two headline measures, using Energy Saving Trust estimates for a gas-heated semi-detached home. Your figure depends heavily on what insulation you already have and how much you heat the house.
| Measure | Typical annual saving (gas-heated semi) | Notes |
|---|---|---|
| Cavity wall insulation | Around £180 to £260 | Free in roughly 90% of suitable homes under the scheme |
| Loft insulation (none to 270mm) | Up to around £580 | Far smaller if topping up existing insulation |
| Loft insulation (top-up, 100mm to 270mm) | Around £135 | Cheaper job, smaller saving |
Savings are Energy Saving Trust estimates for a gas-heated semi-detached home in Great Britain, based on a gas rate of 7.97p per kWh, Ofgem cap October to December 2026. Your saving varies with property size, heating use and existing insulation.
If you want to understand the individual jobs in detail, see our guides to cavity wall insulation and loft insulation.
How the application worked
The process was the same whether you went in through a supplier, a local authority or an installer. Knowing the shape of it is still useful, because the schemes replacing GBIS work in much the same way.
- Eligibility check. You confirmed your council tax band, EPC rating and, for the low-income route, your benefits or income. The government ran an online referral service that pointed eligible homes towards participating suppliers.
- Survey. An accredited installer carried out a retrofit assessment of the property. This decided the right measure and whether any pre-work, such as fixing damp or a roof, was needed first.
- Quote and contribution. For the general group, you were told what you would pay. For the low-income group, the measure was free.
- Installation. Once approved, the installer scheduled and fitted the work, which Ofgem then verified.
One warning that applied throughout the scheme still applies to any insulation grant: be wary of unsolicited cold calls and doorstep sellers claiming to offer free government insulation. Genuine help came through accredited installers and official referral routes, never through pressure to sign on the spot.
The scheme has closed: where to get help now
GBIS was always time-limited. The official referral service closed at the end of March 2026 once suppliers had met their obligations, so you can no longer make a new GBIS application. The work it did has not stopped, though; it has moved into other programmes.
- ECO4 is the closest direct replacement for low-income households and runs to the end of 2026. It is fully funded for those who qualify and covers deeper measures than GBIS did. See our ECO4 guide.
- The Warm Homes Plan is the government's overarching strategy from 2027 onwards, consolidating the patchwork of older schemes into fewer, better-funded programmes. The Warm Homes: Local Grant, run by local authorities rather than suppliers, targets fuel-poor households in the least efficient homes.
- The Boiler Upgrade Scheme remains the main grant for heat pumps if you are looking at your heating system rather than your fabric. Our Boiler Upgrade Scheme guide and heat pumps explained cover that side.
Schemes like these change their rules, amounts and deadlines often, so always check the current position on the official Ofgem or GOV.UK pages before you rely on any figure in this article.
The bottom line
GBIS did a straightforward job well: it took the cheapest, most effective insulation measures and put them within reach of millions of households, including many who were not on benefits. If you went through it, the cavity wall or loft insulation you got is quietly trimming your gas bill every winter and will keep doing so for decades with no maintenance.
If you missed it, do not assume the door is shut. ECO4, the Warm Homes: Local Grant and the wider Warm Homes Plan all carry the same idea forward, and the measures themselves are worth doing even if you end up paying for them yourself. Insulating walls and lofts is still the single best-value thing most people can do to cut heating costs, well ahead of swapping appliances or chasing a cheaper tariff. Pair good insulation with sensible thermostat settings and a look at your standing charges, and a cold, expensive home becomes a warm, affordable one.