ECO4 was the UK government’s largest domestic energy efficiency programme, delivering free insulation and low-carbon heating to fuel-poor households over four years. Understanding the scheme’s structure helps clarify what current successor schemes offer — and what you may still be entitled to if you were assessed before the scheme closed.
For a full overview of grants and funding, see the Grants and Schemes hub.
How ECO4 Worked
The scheme obliged large energy suppliers (British Gas, EDF, E.ON, Octopus, OVO, Scottish Power, and others) to spend a fixed annual amount funding home improvements. Households did not pay energy suppliers — the supplier funded the work through their statutory obligation.
The typical process:
- Household contacts an energy supplier, approved installer, or applies via Simple Energy Advice
- Home assessment carried out (EPC survey and condition report)
- Eligibility confirmed against benefit and income criteria
- Approved ECO4 installer carries out the improvements
- Household pays nothing
The “whole-house” requirement was the defining feature of ECO4: installers had to raise the property’s EPC rating by at least one band (e.g. from E to D), not simply fit one isolated measure. This meant ECO4 improvements were often more comprehensive than GBIS works.
Eligibility Routes
Benefit Route
Receipt of any of the following:
- Universal Credit (note: some income thresholds apply)
- Pension Credit (any element)
- Income-based JSA or ESA
- Housing Benefit
- Child Tax Credit or Working Tax Credit (household income under £31,000)
- Income Support
- Disability Living Allowance or PIP (with income test)
LA Flex Route (Flexible Eligibility)
Local authorities could nominate households without qualifying benefits if:
- EPC rating D–G
- Household income under £31,000 (or in or at risk of fuel poverty)
- Confirmed by local authority officer or partner organisation
This route made ECO4 accessible to households that were struggling with energy costs but not receiving benefits — particularly important for the self-employed, those with variable income, or those recently moved off benefits.
What ECO4 Covered vs What It Did Not
| Covered | Not covered |
|---|---|
| Loft insulation | New gas boilers (except first-time CH) |
| Cavity wall insulation | Solar panels (generally) |
| Solid wall insulation (internal or external) | Double glazing on its own |
| Underfloor insulation | New roofs |
| Flat roof insulation | External building work |
| Air source heat pumps | Cosmetic improvements |
| First-time central heating | Repairs to existing appliances |
| Smart heating controls |
Worked Example — Benefit Recipient, Solid Walls
Household profile: Mid-terrace Edwardian house (1905), EPC E, gas central heating (old combi boiler), owner-occupier. Household on Universal Credit (no children, income from part-time work).
- Eligible via benefit route (Universal Credit)
- Home assessment: EPC E, solid brick walls (no cavity), 100mm loft insulation
- Measures recommended: internal solid wall insulation (raises to EPC D), loft insulation top-up to 270mm, new smart heating controls
- Cost to household: £0
- Estimated combined value of works: ~£12,000
- Estimated annual saving on heating: ~£450–£700
The Whole-House Requirement
Unlike GBIS (which funds one measure), ECO4 required that the combination of measures installed raised the property’s EPC rating. This had two consequences:
- More improvements per household — a loft insulation-only install was often not enough on its own; the installer would also need to do wall or floor insulation
- Surveyor discretion matters — the surveyor’s assessment determined which measures were needed to achieve the band uplift
If an installer told you only one measure was eligible and that wasn’t enough for the EPC uplift, they were likely referring to ECO4 rules correctly — additional measures would be needed to comply.
What to Do If You Were Mid-Application When ECO4 Ended
ECO4 closed to new applications in March 2026. If you were in the assessment or installation pipeline:
- Work surveyed and confirmed before closure should have been honoured under the supplier’s ECO4 obligation — contact the installer or your energy supplier
- If an installer has not proceeded, contact Ofgem’s consumer helpline or your referring energy supplier
- For new applicants, relevant alternatives are:
- GBIS (insulation only, no heat pumps)
- HUG2 (if off-gas grid)
- Boiler Upgrade Scheme (heat pump grant, income-neutral)
- Nest Wales (if in Wales) or Warmer Homes Scotland (if in Scotland)
Quality of Work and Complaints
All ECO4 installers were required to be TrustMark-registered and hold relevant MCS certification for heat pump installations. If you had ECO4 work done and have concerns:
- Contact the installer first — they remain liable for workmanship after scheme closure
- Escalate to your energy supplier if the installer was referred by them
- Contact TrustMark (trustmark.org.uk) for persistent quality disputes — they operate a dispute resolution process
- Ofgem handles supplier-level compliance but does not resolve individual household installation disputes
Housing Tenure and ECO4
| Tenure | Can access ECO4? | Conditions |
|---|---|---|
| Owner-occupier | Yes | Standard eligibility applies |
| Private renter | Yes | Landlord must give written consent |
| Social housing tenant | Limited | Primarily covered by separate social housing decarbonisation fund |
| Private landlord (renting out) | Can arrange on behalf of tenant | Tenant must be eligible; MEES may independently require improvement |
Comparing ECO4, GBIS, and HUG2
| Feature | ECO4 | GBIS | HUG2 |
|---|---|---|---|
| Benefit/income required | Yes | Low income group only | Yes (under £36k) |
| General eligibility | No (LA Flex only) | Yes (council tax A–D) | No |
| Off-gas required | No | No | Yes |
| Insulation | Yes | Yes — one measure | Yes |
| Heat pumps | Yes | No | Yes |
| Solar panels | Rarely | No | Some LAs |
| Cost to household | £0 | Free to small contribution | £0 |
| Scotland/Wales | Yes | Yes | No (England only) |
After ECO4 — What Succeeds It
At the time of writing, the following programmes are the main successors:
- GBIS — if still running, covers insulation (check current status)
- Boiler Upgrade Scheme — £7,500 grant toward heat pump (all income levels)
- LA Flex — may continue under any successor obligation scheme
- ECO5 — expected government successor obligation; check gov.uk for latest