Government Grants for Insulation: ECO4 and Great British Insulation Scheme Explained

04 June 2025

If your home loses heat through poorly insulated walls, lofts or floors, you could be paying far more in energy bills than you need to. Two UK government-backed schemes — ECO4 and the Great British Insulation Scheme (GBIS) — are designed to help households fund insulation upgrades at little or no cost. This guide explains how each scheme works, who qualifies and how to apply.

What Is the ECO4 Scheme?

ECO4 (the Energy Company Obligation, fourth phase) obliges large energy suppliers to fund energy-efficiency improvements in homes across Great Britain. Instead of applying to the government directly, you apply through an approved installer or energy supplier, which then claims the cost back from the scheme.

ECO4 focuses on whole-house improvements. Rather than simply topping up loft insulation, an assessor looks at your property as a whole and may recommend several measures together, such as:

Loft or roof insulation
Cavity wall or solid wall insulation
Underfloor insulation
Room-in-roof insulation
First-time central heating or heating upgrades in some cases

The scheme runs until March 2026 and is aimed primarily at low-income and vulnerable households.

Who Qualifies for ECO4?

Eligibility generally depends on a combination of your household circumstances, benefits and the energy performance of your home. You are most likely to qualify if someone in your household receives a means-tested benefit such as Universal Credit, Pension Credit, Income Support, Child Tax Credit or Working Tax Credit. Households on certain disability or carer-related benefits may also be included.

Your property usually needs to have an Energy Performance Certificate (EPC) rating of D, E, F or G to be considered. If you do not receive benefits, you may still qualify under what is known as "route 4" — a flexibility route where local authorities or suppliers can refer households judged to be at risk of fuel poverty, even without benefit entitlement.

What Is the Great British Insulation Scheme?

The Great British Insulation Scheme (formerly known as ECO+) is a complementary programme aimed at a wider group of households. Where ECO4 targets low-income homes, GBIS is designed to help those living in homes with poor energy efficiency — typically EPC ratings of D to G — who may not receive benefits at all. It focuses mainly on single, cheaper measures, most commonly loft or cavity wall insulation, rather than a full package of upgrades.

Because the scheme covers a broader group, the funding per household may be lower, meaning some homeowners receive heavily subsidised insulation rather than fully funded work. Nonetheless, for many households it can significantly reduce the upfront cost of a project that would otherwise run into the hundreds or thousands of pounds.

How the Two Schemes Differ

Income basis: ECO4 is aimed at low-income and vulnerable households; GBIS extends support to a wider group based on property efficiency.
Scope: ECO4 often funds multiple, whole-house measures; GBIS typically funds one main insulation measure.
Cost: ECO4 measures are frequently free; GBIS may involve a partial contribution from the homeowner.
Property rating: Both generally target homes with lower EPC ratings, though the thresholds differ slightly.

How to Apply

The application process is broadly similar for both schemes:

Check your EPC rating online to confirm your property is likely eligible.
Gather evidence of any benefits you receive, if applicable.
Contact a registered installer or your energy supplier, or use the government's online eligibility checker.
Arrange a survey or assessment of your home.
If approved, the installer schedules and carries out the work, with funding applied directly.

Practical Tips Before You Start

Only use installers registered with the relevant scheme and check that they are accredited by a recognised body. Be cautious of cold callers or unsolicited phone calls promising "free grants" — legitimate applications begin with a proper assessment, not a doorstep offer. Finally, remember that grant funding is finite and demand fluctuates, so if you believe you qualify, it is worth applying sooner rather than later. Insulation remains one of the most cost-effective ways to cut bills and improve comfort, and these schemes make it far more affordable.