- ECO4 is a government-backed energy-efficiency scheme aimed at helping low-income and vulnerable households improve their homes.
- The scheme has been extended and now ends on 31 December 2026, not 31 March 2026.
- It can fund free or subsidised upgrades such as insulation, heating improvements and, in some cases, free solar panels.
- Eligibility depends on your circumstances, including income, benefits, health, housing tenure and the energy efficiency of your home.
- Window upgrades can be covered under ECO4, including single-to-double glazing and some improved double glazing, though funding is not guaranteed.
- You cannot simply choose any upgrade you want – suppliers decide which retrofit projects and measure packages they will fund.
- There will be no direct successor to ECO4 after it closes, with future support expected to sit under the government’s Warm Homes Plan instead.
- If you think you may qualify, it is worth applying sooner rather than later, as the current scheme is now on a fixed countdown to closure.
If the upfront cost of solar panels is putting you off, the government’s ECO4 scheme is one of the best solar panel grants there is and may still offer a route to support. Designed to help low-income and vulnerable households improve their home’s energy efficiency, the scheme can cover measures such as insulation, heating upgrades and, in some cases, solar panels.
Originally due to end in March 2026, ECO4 has now been extended until 31 December 2026, giving eligible households a little longer to apply. After that, the government has said there will be no direct successor to ECO4, with future support instead expected to sit under its wider Warm Homes Plan.
In this guide, we explain who may qualify, what improvements the scheme can fund, and how to apply before the current deadline.
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What is the ECO4 scheme and how does it work?
ECO4 is part of the government’s broader Energy Company Obligation programme, designed to reduce carbon emissions and tackle fuel poverty. If you or someone you live with qualifies for state benefits, then the ECO4 grant could help you. ECO4 is a government-backed energy efficiency scheme designed to tackle fuel poverty and reduce carbon emissions. As the name suggests, it’s the fourth phase of the Energy Company Obligation, and it runs until 31 March 2026. It is funded by major energy companies and regulated by Ofgem.
The ECO4, therefore, is not a traditional government grant; rather, it is an obligation from the government on energy suppliers to fund energy efficiency upgrades in eligible households.
ECO4 eligibility: who qualifies for the ECO4 grant?
You may qualify if your household income is less than £31,000, you live in private housing (i.e. not council-owned), and you receive one of the following benefits:
- Child Tax Credit
- Working Tax Credit
- Universal Credit
- Pension Guarantee Credit
- Pension Savings Credit
- Income Support
- Income-based Jobseeker’s Allowance (JSA)
- Income-related Employment and Support Allowance (ESA)
- Child Benefit
- Housing Benefit
If you own your house, it must be rated D or worse and if you rent, E or worse for energy efficiency.
You can find out what energy rating your home has on the government website. It covers properties in England, Wales or Northern Ireland. This includes homes, business properties and public buildings.
What does the ECO4 grant cover and what’s not included?
You can apply through your energy provider for funding worth up to £10,000 to make your home more energy efficient.
The scheme is for broad energy efficiency, so you might find that insulation and a smart thermostat are better uses of the funding for your energy use.
What the ECO4 scheme covers
- Insulation upgrades, including for your loft, cavity wall, and solid wall
- Heating system upgrades, including for efficient boilers and heat pumps
- Renewable energy installations, including free solar panels
What the ECO4 scheme does not cover
- New doors or windows
- Properties with a D or higher Energy Performance Certificate rating
- Projects that combine ECO4 with other funding sources (In some cases, ECO4 Flex may allow complementary funding with strict conditions, but usually it cannot be combined)
Does ECO4 cover windows?
Yes, ECO4 can cover window upgrades, but it is not a blanket free-window scheme. Ofgem’s guidance says window glazing is an eligible ECO4 measure and can be installed as either single-to-double glazing or improved double glazing, which means replacing older double glazing that no longer meets current building regulations.
That said, window replacements are usually not the most straightforward measure to get funded. Ofgem notes that while replacement window glazing is eligible under ECO4, it is still up to energy companies to decide which projects and measure packages they will fund. In practice, that means windows may be approved as part of a wider whole-house upgrade, rather than as a simple standalone request to replace otherwise functioning windows.
There are also some limits on what counts. Ofgem’s product guidance says window glazing under ECO4 covers factory-made sealed window units and does not include secondary glazing.
Pros and cons of the ECO4 scheme
Pros
- Can fully or partly fund energy-saving upgrades for eligible households, reducing upfront costs.
- May cover a range of improvements, including insulation, heating upgrades and some renewable measures.
- Aims to help low-income and vulnerable households cut energy use and improve home warmth.
- Has been extended until 31 December 2026, giving applicants more time to apply.
Cons
- Eligibility is limited, so many households will not qualify.
- Not every measure is guaranteed, even if it is technically covered by the scheme.
- The application process can be confusing, especially if you need to apply via a supplier, installer or local authority.
- ECO4 is now a short-term scheme, with no direct successor planned after it ends.
How to apply for the ECO4 scheme
You can contact your local council to check if they are participating in ECO4 Flex, or you can go directly to an energy supplier.
Ofgem maintains a list of companies taking part.
These include:
- British Gas
- E (Gas & Electricity) Ltd
- E.ON UK Solutions
- Ecotricity
- EDF
- Octopus Energy
- Outfox the Market
- OVO
- Scottish Power
- So Energy (Including ESB Energy)
- The Utility Warehouse
- Utilita Energy Ltd
Be cautious of third-party websites claiming to offer access to ECO4. Many are not affiliated with the scheme. Some may charge fees for services you can access for free; others may be scams. You can read Ofgem’s scam advice to learn more.
What to do if your ECO4 home upgrade goes wrong
If you aren’t happy with the work that’s done on your home, first contact the supplier. If that doesn’t work, Citizens Advice can offer support.
The ECO4 scheme is regulated by Ofgem, so any disputes around ECO4 eligibility, grant misuse, or poor workmanship may also fall under their oversight.
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