ECO4 and GBIS Grant Schemes Explained for Installers

Summary

ECO (the Energy Company Obligation) has run in successive phases since 2013, each tightening the targeting toward genuinely low-income and vulnerable households and broadening the range of eligible measures (from insulation-only in early phases to heating systems, first-time central heating, and other measures in later phases). ECO4 is the current/most recent phase, obligating larger energy suppliers to deliver energy efficiency improvements to a target number of low-income and vulnerable homes, funded through supplier obligation rather than general taxation (the cost is recovered through energy bills across all customers).

GBIS was introduced as a genuinely distinct scheme — not another ECO phase — specifically to broaden insulation-measure eligibility beyond the low-income-only targeting of ECO4, recognising that many households in lower EPC-band, lower council-tax-band properties were missing out on insulation support despite not meeting ECO4's stricter low-income qualifying benefits criteria. GBIS is deliberately narrower in measure scope (largely insulation) but broader in household eligibility.

For installers, the practical distinction that matters is: both schemes route through TrustMark-registered installers working to PAS 2035/PAS 2030, both require the property/household to be checked against the specific scheme's eligibility criteria before work starts (retrospective claims don't work), and getting the eligibility check wrong is the single most common reason installers don't get paid for completed work.

Key Facts

• ECO4 — current phase of the Energy Company Obligation; running under current government rules from 2022 with an end date around March 2026 ****.
• ECO4 funding mechanism — obligated (larger) energy suppliers fund measures; cost recovered through energy supplier obligations, ultimately reflected in energy bills rather than general taxation.
• ECO4 eligibility — targeted at low-income and vulnerable households, assessed via qualifying benefits, and (for the "ECO4 Flex" route) via local authority-defined additional criteria for households in fuel poverty risk not otherwise captured by the standard benefits list.
• GBIS (Great British Insulation Scheme) — a distinct scheme (sometimes referred to as "ECO+") focused primarily on insulation measures, with eligibility based on EPC band (typically D–G) and council tax band thresholds, plus a low-income eligibility route similar to ECO4's.
• GBIS measure scope — narrower than ECO4: predominantly insulation measures (loft, cavity wall, external/internal wall insulation, room-in-roof, park home insulation), rather than the full range (including heating measures) available under ECO4.
• PAS 2035/PAS 2030 requirement — both schemes require retrofit work to be delivered through a PAS 2035-compliant process with a Retrofit Coordinator, and installers to hold PAS 2030 certification for the specific measure.
• TrustMark registration — installers must generally be TrustMark-registered (or working under a TrustMark-registered business) to deliver funded work under either scheme.
• Pre-work eligibility checks are mandatory — the property/household eligibility (benefits check, EPC band, council tax band as applicable) must be confirmed before installation; work cannot be retrospectively claimed against the scheme if eligibility wasn't verified up front.
• "ECO4 Flex" — a route allowing local authorities to refer or declare households eligible under locally-defined fuel poverty criteria, broadening ECO4 eligibility beyond the standard national benefits list.
• Funding is per-measure, calculated by score — under ECO schemes, measures earn a score based on their estimated carbon/bill savings, and suppliers must meet an overall obligation target rather than a fixed number of installations — this affects which measures a scheme administrator prioritises funding.
• Risk to installers of getting eligibility wrong — if a household turns out not to meet the scheme's eligibility criteria after work has been completed, the installer/scheme administrator risks not being able to claim funding for that job, which is a real commercial risk if the eligibility check wasn't done properly up front.

Quick Reference Table

Detailed Guidance

Choosing the right scheme for a given household

ECO4 / GBIS ELIGIBILITY TRIAGE
-------------------------------
Household on qualifying low-income benefit?
   -> Check ECO4 first (broader measure scope)

Household NOT on qualifying benefit, but:
  - Property EPC band D, E, F or G, AND
  - Property in a lower council tax band?
   -> Check GBIS (insulation-focused)

Household in genuine fuel poverty risk but doesn't
fit either standard criteria?
   -> Check ECO4 Flex — local authority may be able
      to declare eligibility under local criteria

Always run the actual current eligibility check through the scheme administrator or a registered eligibility-checking tool rather than relying on a general rule of thumb — criteria, qualifying benefit lists and EPC/council-tax thresholds are updated periodically.

Why PAS 2035 sits underneath both schemes

Both ECO4 and GBIS require the retrofit work to be delivered through a PAS 2035-compliant process — a whole-building risk assessment, a named Retrofit Coordinator, and installation by PAS 2030-certified contractors. This isn't a scheme-specific add-on; it's the same underlying retrofit quality framework that now underpins essentially all government-backed domestic retrofit funding, precisely to avoid the isolated-measure moisture/damp problems that affected earlier scheme phases.

The commercial risk of skipping the eligibility check

The single most common reason installers report not getting paid for ECO4/GBIS work is completing the installation before the household/property eligibility was properly confirmed — then finding the claim rejected because the qualifying criteria weren't actually met. Building the eligibility check into the sales/survey process, before any work is scheduled, protects against this.

Frequently Asked Questions

What's the practical difference between ECO4 and GBIS for a homeowner?

ECO4 is aimed at low-income and vulnerable households and covers a broad range of measures (insulation and heating). GBIS is aimed more broadly at properties with a poor EPC rating regardless of income (subject to a council tax band threshold), but only for insulation measures. A household might qualify for one, both, or neither, depending on their specific circumstances — the eligibility check needs to be done against the current criteria for each scheme separately.

Can I install measures first and claim funding afterwards?

No — eligibility must be verified before work starts. Installing first and attempting to claim retrospectively is the most common way installers end up unpaid for completed work, because the funding claim depends on documented pre-work eligibility evidence.

Does GBIS cover heat pumps or boilers?

No — GBIS is focused predominantly on insulation measures. Heating measures (including heat pumps, boiler upgrades, first-time central heating) generally sit under ECO4's broader measure scope, or under separate schemes like the Boiler Upgrade Scheme (BUS) for heat pumps specifically.

Do I need any particular certification to install under these schemes?

Yes — installers need to be TrustMark-registered (or working under a TrustMark-registered business) and hold PAS 2030 certification for the specific measure being installed, with the overall project run under a PAS 2035-compliant process with a named Retrofit Coordinator.

Regulations & Standards

• Energy Company Obligation (ECO) — ECO4 Order (secondary legislation under the Gas Act 1986/Electricity Act 1989 obligation framework) — the legal basis for ECO4.

• PAS 2035:2019 / PAS 2030:2019 — the retrofit process and installation standards both schemes require.

• TrustMark — the government-endorsed scheme installers must generally be registered under to deliver funded work.

• Energy Performance of Buildings (England and Wales) Regulations 2012 — underpins the EPC bands used in GBIS eligibility criteria.

• GOV.UK — ECO4 scheme guidance — official ECO4 rules and eligibility.

• GOV.UK — Great British Insulation Scheme (GBIS) — official GBIS eligibility and application guidance.

• Ofgem — ECO scheme information — scheme administration and supplier obligation detail.

• TrustMark — retrofit scheme requirements — installer registration and PAS 2035/2030 requirements.

• pas 2035 retrofit coordinator guide — the retrofit process standard underpinning both schemes

• mees regulations — related landlord energy efficiency obligations

• bus grant guide — the Boiler Upgrade Scheme, the separate route for heat pump funding

• domestic epc changes 2025 — EPC context relevant to GBIS eligibility