The Great British Insulation Scheme (GBIS) explained

In October 2025, the National Audit Office reported on failures with the quality of external and internal wall insulation under government schemes.

In response, the UK Government is offering affected homes free audits to identify any issues. TrustMark is conducting these audits. If they identify any problems, then TrustMark will arrange for them to be fixed at no cost to you.

Find out more about TrustMark’s free Find & Fix audit offer.

After applying, your energy provider would have been in touch to arrange a free assessment of your property. After this, they’d tell you what kind of insulation you could get support with.

With GBIS, you may have been able to get help to install:

• cavity wall insulation
• loft insulation
• other types of insulation as determined by the assessment

As of April 2025, the most common measure installed through GBIS was cavity wall insulation, which accounted for 41% of all measures installed. This is followed by loft insulation (28%) and heating controls (21%).

You might have qualified for a home insulation grant if your home:

• Had an Energy Performance Certificate (EPC) rating of D to G.
• Was in council tax bands A to D in England or A to E in Scotland and Wales.

If you live in England and Wales, you can check your home’s EPC rating on GOV.UK. You can also check your council tax band on GOV.UK.

If you live in Scotland, you can check your home’s EPC rating on the EPC Register. You can check your council tax band on the Scottish Assessors’ portal.

The scheme was available to homeowners, landlords and tenants.

Depending on the outcome of any assessments, you may have been asked to contribute a proportion of the costs depending on your circumstances and work required. This would have been discussed with you before you agreed to go ahead with an installation.

As your energy supplier would have managed the whole process for you, you wouldn’t receive funding directly to buy insulation yourself, for example.

You wouldn’t have applied for the grant directly. Instead, your energy supplier would have applied for funding on your behalf.

Improving the energy efficiency of your home is a vital part of addressing both the energy crisis and climate emergency. Adding proper insulation and heating controls to your property could save you money on your energy bills too. This is how much it could save a typical house in Great Britain:

• cavity wall insulation – save £240
• heating controls – save £110
• loft insulation – save up to £230
• solid wall insulation – save £330
• floor insulation – save £70

GBIS was designed complement ECO4. They’re different schemes, but this is sometimes confused as some still refer to GBIS by its previous name, ECO+.

GBIS mostly focused on delivering single, lower-cost insulation measures. This was to help as many homes as possible get support through the scheme quickly.

The ECO4 scheme focuses on improving the whole house, where possible.

Read Ofgem’s guide for more information about how GBIS complemented ECO4.

Depending on your circumstances and where you live, you might be eligible for financial support to help:

• make your home more energy efficient.
• install low carbon heating.

Find out what financial support is currently available.

Sign up for Energywire, our monthly newsletter, to get energy saving advice delivered straight to your inbox.

Sign up to our newsletter