GBIS — the Great British Insulation Scheme — closed as planned on 31 March 2026, and its referral pathway is no longer accepting new applications. ECO4 remains open until 31 December 2026, targeted at lower-income and lower-EPC-band households, and the government has confirmed there will be no successor obligation once it ends — the supplier-funded model that has driven millions of UK insulation installs since 2013 will stop. For Derbyshire homeowners, this is the final stretch to access free or heavily subsidised insulation, heating and energy upgrades through ECO4. Here is the timeline, what's still available if you missed GBIS, and the Cor electrical/Gas Safe checks that should follow any install.
The 2026 timeline at a glance
- GBIS — Great British Insulation Scheme: closed 31 March 2026, as planned, with no extension. The general-eligibility referral pathway for loft, cavity-wall and room-in-roof insulation is no longer taking new applications. If you missed it, ECO4 is the route to check next
- ECO4 — the Energy Company Obligation: extended from its original 31 March 2026 deadline by nine months, and live until 31 December 2026. Targeted at lower-income and EPC-band E, F, G households
- After 31 December 2026: no government-confirmed successor scheme. The supplier-funded retrofit model winds down. Future support is likely to be loan-based or grant-by-need rather than a blanket obligation on energy suppliers
- Boiler Upgrade Scheme: separate, continuing. £7,500 grant for heat pumps remains, with a refreshed £2.7bn HM Treasury budget through 2026 (see our separate handyman blog on heat-pump-ready homes)
What an ECO4 install typically delivers
Three install types have been the workhorses across Derbyshire ECO4 (and, until March, GBIS) schemes. Cavity-wall insulation in 1930s-1980s semis and terraces (typically saves £160-£260/year on heating bills per the Energy Saving Trust). Loft insulation top-up to 270-300mm in older houses with thin or compacted insulation (saves £120-£220/year). Boiler replacement for households in fuel poverty whose existing boiler is band C or worse (saves £200-£450/year on a typical 3-bed semi). For homes in EPC bands F or G, ECO4 can also fund external-wall insulation, but the installation cost is much higher and the queue much longer.
What the installer will and won't do — the Cor checks that should follow
ECO4 (and, while it was open, GBIS) installers are TrustMark-accredited and PAS 2030/2035 compliant. They handle the install itself. They do not generally handle adjacent electrical or Gas Safe checks unless explicitly contracted. Three specific checks Derbyshire households should book separately with a qualified contractor after install — whichever scheme the work came through.
1. Post-cavity-fill electrical check
Cavity wall insulation in older Derby homes occasionally compromises existing cables run in the cavity. If you have cables that drop down or run through a cavity wall to garden lights, an external socket or a garage feed, an EICR (Electrical Installation Condition Report) post-fill confirms nothing has been displaced. Cor's electricians offer EICR booking via cor.kirkgroup.uk (see our separate landlord EICR blog for the rules around 5-year renewals).
2. New boiler commissioning and Gas Safe sign-off
ECO4-funded boiler replacements are commissioned by the installer's own Gas Safe engineer. Worth booking a 6-month follow-up service with your own Gas Safe engineer (Cor offers this as a planned service) to ensure pressure, flue, and condensate are all running cleanly. Most ECO4 installs are bedded in by month 4-6, and the first independent service catches anything the installer's commissioning missed.
3. Loft-top-up access and electrical safety
Loft insulation top-ups occasionally cover existing lighting cables that should be in cable supports. Worn cable buried in 300mm of mineral wool can overheat. A quick visual EICR of loft cable runs is a 30-minute job that's worth the peace of mind.
Practical Derbyshire shopping list before the ECO4 deadline
If you're a Derbyshire homeowner, the practical steps before ECO4 ends:
- Check your EPC rating on the government EPC register — if you're band E-G and on a lower income, ECO4 may still be open to you (GBIS closed 31 March 2026 and is no longer an option)
- If you missed GBIS, get assessed for ECO4 instead — the assessment is typically free, and installs are booked subject to scheme capacity, so don't leave it to the last few weeks before 31 December 2026
- If your boiler is more than 10 years old and your household sits in or near fuel poverty, ask the ECO4 route specifically about boiler replacement
- Book a post-install EICR with Cor for cavity-wall and loft insulation jobs — typically a half-hour visit
- Book a 6-month boiler service with Cor's Gas Safe engineers if you've had a new boiler fitted under ECO4 — catches commissioning issues early
"Once ECO4 ends, the supplier-funded model that has driven millions of insulation installations since 2013 will cease."
After December 2026 — what's likely next
The government has signalled that future retrofit support is likely to be more targeted and less universal — grant-by-need, loan-based, or routed through local authority programmes rather than as a blanket obligation on energy suppliers. The Boiler Upgrade Scheme continues, the Warm Homes Plan elements are still being defined, and local authority schemes (often topped-up from devolved funding) will continue. But the supplier-funded universal retrofit era — free insulation for almost any older home in the right Council Tax band — ends with ECO4.
Book a post-install Cor check
Cor offers EICRs and Gas Safe boiler services for Derby and Derbyshire homes — ideal as a follow-up to an ECO4 install, or a GBIS install from before March 2026. Same-day capacity where available; planned bookings within 5-7 working days at standard rates.
Published by Kirk Group Editorial
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