ECO4 and insulation grants

What these schemes are, in one paragraph

ECO4 and the Great British Insulation Scheme are government-backed programmes paid for by the larger energy suppliers. They fund insulation, and in some cases heating upgrades, for households that would struggle to pay for them. ECO4 is aimed mainly at lower-income and benefits households in poorly rated homes, and can cover several measures at once. The Great British Insulation Scheme is narrower, usually funding one insulation measure, and reaches a slightly wider group. Both have changed since they started and will change again, so treat this page as a map and check the current rules with the scheme before you rely on anything.

Are they still open?

Check this first. Both schemes were set up to run for a fixed period, and the government has signalled that support for lower-income homes is moving towards new programmes under its Warm Homes Plan. Work already agreed may still be finishing, new routes may have opened, and the names may change. Before you spend time on an application, confirm on gov.uk or with your council what is taking applications today. The general points below still help, because whatever replaces these schemes is likely to target similar households and similar measures.

How ECO4 works

ECO stands for Energy Company Obligation. The government obliges larger energy suppliers to fund energy saving work in homes, and the suppliers pay approved installers to deliver it. You do not usually pay the supplier anything, and you do not have to switch supplier.

ECO4 is the fourth version of the scheme. In general terms:

• Who it is for: households on certain means-tested benefits, or on low incomes, living in homes with a low energy rating. Councils can refer some households through what is called flexible eligibility, sometimes known as LA Flex, which covers low-income homes and people whose health is affected by a cold home.
• What it pays for: loft, cavity wall, solid wall and underfloor insulation, heating controls, and in some cases a heat pump, a replacement boiler or other heating. The aim is to lift the whole home’s energy rating, so several measures may be bundled.
• How much you pay: often nothing, but some jobs are part-funded and you may be asked to contribute. Ask for any contribution in writing before work starts.

The Great British Insulation Scheme

The Great British Insulation Scheme is a smaller, supplier-funded scheme aimed at insulation alone. In general terms it reaches lower-income households and some homes in lower council tax bands with poor energy ratings, and usually funds a single measure such as cavity wall or loft insulation. It does not normally fund a heat pump.

How they compare with heat pump grants

All figures and rules checked October 2026. Our Boiler Upgrade Scheme guide covers the heat pump grant in detail, and our Home Energy Scotland guide covers Scotland. Northern Ireland runs its own schemes; see our Northern Ireland heating grants guide.

Why insulation matters for a heat pump

A heat pump runs at a lower flow temperature than a gas boiler. Flow temperature is the heat of the water sent to your radiators. Lower flow temperatures make the heat pump more efficient, but they only keep the house warm if heat is not leaking out quickly. Insulation cuts that heat loss.

That has two practical effects:

1. A smaller heat pump may do the job. The size of a heat pump is set by the home’s heat loss. Less heat loss can mean a smaller, cheaper unit. See what size heat pump you need.
2. Fewer radiators may need changing. Lower heat loss can mean your existing radiators are big enough, which can save £300 to £600 per radiator (typical, checked October 2026).

The Boiler Upgrade Scheme itself does not require insulation. If your home is a likely ECO4 candidate, though, it makes sense to sort insulation first, then size the heat pump on the improved house.

How to apply

1. Check which schemes are open and their current eligibility rules on gov.uk.
2. Contact your energy supplier or your council and ask which scheme you may qualify for.
3. Expect a home visit to assess the property and its energy rating.
4. Get any contribution, the list of measures and the installer’s details in writing.
5. Make sure installers are properly certified for the work they carry out.

Be wary of cold callers offering “free” insulation or heat pumps. Genuine schemes exist, but so do people who use the name. Check the company yourself before agreeing to a survey.

Where City Boiler fits

City Boiler is not an installer and does not run these schemes. We connect homeowners with independent MCS-certified heat pump installers. If you may qualify for ECO4, check that first, because it could pay for work you would otherwise fund yourself. If you do not qualify, the Boiler Upgrade Scheme is usually the main route to a cheaper heat pump in England and Wales.