- ECO4 is a government-backed energy-efficiency scheme designed to help low-income and vulnerable households make their homes warmer, cheaper to run, and more energy-efficient.
- The scheme has been extended and is now due to end on 31 December 2026, rather than 31 March 2026.
- ECO4 can fund free or subsidised home upgrades, including insulation, heating improvements and, in some cases, solar panels.
- Eligibility depends on several factors, including your income, benefits, health, housing tenure and the energy efficiency rating of your home.
- Some window upgrades can be covered under ECO4, including single-to-double glazing and certain improvements to existing double glazing, but funding is not guaranteed.
- You cannot simply choose which upgrade you want. Energy suppliers decide which homes and packages of measures they are willing to fund.
- There is not expected to be a direct successor to ECO4 after it closes, with future support likely to sit under the government’s wider Warm Homes Plan.
- 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.
The ECO4 scheme is one of the main government-backed ways for low-income and vulnerable households to improve the energy efficiency of their homes. It can help fund free or subsidised upgrades such as loft and wall insulation, heating improvements, new controls and, in some cases, solar panels or window upgrades.
Although ECO4 is often discussed alongside solar panel grants, it is not a solar-only scheme. Its main purpose is to reduce energy use, lower bills and make poorly insulated homes warmer. The exact support available depends on your property, your circumstances and the package of improvements an energy supplier is willing to fund.
The scheme was originally due to close in March 2026, but has now been extended until 31 December 2026. After that, the government has said there will be no direct successor to ECO4, with future support expected to sit under the wider Warm Homes Plan instead.
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. In this guide, we explain who may qualify for ECO4, what home improvements can be covered, how the application process works and why it is worth checking your eligibility before the current scheme ends.
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What is the ECO4 scheme and how does it work?
ECO4 is the fourth phase of the Energy Company Obligation, a government energy-efficiency scheme funded by medium and large energy suppliers and regulated by Ofgem. It is designed to help low-income, fuel-poor and vulnerable households improve their homes through measures such as insulation, heating upgrades and, in some cases, renewable technologies. ECO4 now runs until 31 December 2026.
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?
Eligibility usually depends on a combination of your benefits, income, property type, housing tenure and EPC rating. Some households may qualify through ECO4 Flex if they are on a low income or are considered vulnerable by their local authority. You may be eligible if you live in private housing and receive one of the following benefits:
- Universal Credit
- Pension Guarantee Credit
- Pension Savings Credit
- Income Support
- Income-based Jobseeker’s Allowance
- Income-related Employment and Support Allowance
- 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?
ECO4 funding varies by property and is not offered as a fixed cash grant. If your home qualifies, a supplier or installer will assess which package of energy-efficiency measures may be suitable and whether they can be fully or partly funded.
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 secondary glazing, or window replacements that do not meet ECO4 eligibility rules or are not approved by a supplier as part of a funded package
- Homes that already meet the relevant EPC threshold. In general, owner-occupied private homes must be rated D, E, F or G, while private rented and social housing properties usually need to be rated E, F or G
- 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.
Before agreeing to work, check who is funding the measure, who will install it, what guarantees apply and who you should contact if something goes wrong. Be wary of cold callers or third-party websites asking for fees to access ECO4. If you are unsure whether an offer is genuine, contact your local council or the energy supplier the installer says they represent.
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