ECO4 is Ending: Why March 31 is the Hard Deadline for Legacy Heating Grants
The Energy Company Obligation (ECO) scheme has been a vital source of funding for energy efficiency improvements in the UK for over a decade. The current iteration, ECO4, was originally scheduled to conclude on March 31, 2026. While the government has recently announced a nine-month extension for the main scheme, the original date of March 31 remains a critical, hard deadline for a related scheme and marks a significant shift away from traditional "legacy" heating grants .For homeowners, tenants, and landlords, understanding the true meaning of this deadline is essential to securing funding for home upgrades before the landscape changes permanently.
The Dual Deadline: ECO4 vs. GBIS
The confusion surrounding the deadline stems from the government's decision to treat two major schemes differently:
Scheme
Original End Date
New End Date
Primary Focus
ECO4
March 31, 2026
December 31, 2026
Whole-house retrofit, low-carbon heating (heat pumps), and insulation for low-income households.
Great British Insulation Scheme (GBIS)
March 31, 2026
No Extension
Single insulation measures (e.g., loft or cavity wall) for a broader range of households.
The government's decision to end the Great British Insulation Scheme (GBIS) as planned on March 31, 2026, provides clarity for the supply chain and allows resources to be focused on the extended ECO4 program . This means that the opportunity to receive funding for single, standalone insulation measures under GBIS is a "use it or lose it" scenario with a firm deadline.
The End of "Legacy" Heating Grants
While the ECO4 scheme itself is extended, its focus has always been on a "Fabric First" approach and the transition to low-carbon heating. This means that the grants for replacing non-condensing gas boilers—often referred to as "legacy heating grants"—have been heavily restricted under ECO4 and are being phased out entirely.The extension of ECO4 to December 2026 is not a reprieve for traditional boiler replacements. Instead, it is intended to:1.Bridge the Gap: Provide a smoother transition to the successor scheme, the Warm Homes Plan, which will be the primary vehicle for energy upgrades from 2027 onwards [2].2.Focus on Quality: Allow obligated energy suppliers and installers additional time to complete existing projects and remediate any non-compliant installations, addressing concerns raised by the National Audit Office .3.Drive Low-Carbon Heat: Continue the push for heat pump installations, which are the primary heating measure supported by ECO4.The underlying policy direction is clear: government funding is moving away from fossil fuel heating and towards comprehensive, whole-house retrofits that include insulation and heat pumps.
What Landlords and Tenants Must Do Now
The period between now and the end of 2026 is a critical window for accessing significant grant funding. Property owners should take immediate action based on the scheme that best suits their needs:
Action for GBIS (Deadline: March 31, 2026)
If your home only requires a single insulation measure (like loft or cavity wall insulation) and you do not qualify for the full ECO4 scheme, you must act now. The GBIS is the last major scheme offering single-measure insulation grants to a broad range of households, and the application window closes definitively on March 31.
Action for ECO4 (Deadline: December 31, 2026)
If your property has an EPC rating of E, F, or G and you are a low-income household (or your tenant is), the extended ECO4 scheme offers the chance for a fully funded, whole-house retrofit.•Prioritise Retrofit: ECO4 mandates a "Fabric First" approach. Focus on getting wall and loft insulation installed first, as this is a prerequisite for a heat pump.•Seek Low-Carbon Heat: Use the scheme to install a heat pump. The combination of fabric measures and a heat pump is the most effective way to meet the 2030 EPC C target.•Engage an Installer: The process is managed by energy suppliers and their partners. Contacting an ECO-accredited installer immediately is the first step to securing a place in the queue before the December 2026 final deadline.The March 31 deadline for GBIS is a stark reminder that the era of simple, single-measure grants is rapidly drawing to a close. The future of government funding lies in comprehensive, low-carbon retrofits, making the next few months a crucial time for property owners to secure the support they need.
References
[1] [Extending the ECO4 end date: government response (HTML)](https://www.gov.uk/government/consultations/extending-the-eco4-end-date/outcome/extending-the-eco4-end-date-government-response-html ) - GOV.UK[2]: https://www.gov.uk/government/news/families-to-save-in-biggest-home-upgrade-plan-in-british-history)-GOV.UK(ReferencingtheWarmHomesPlan "Families to save in biggest home upgrade plan in British history"[3]: https://heat1.co.uk/what-happens-to-eco4-applications-when-funding-ends/)-Heat1(Referencingthefundingexhaustionrisk "What Happens to ECO4 Applications When Funding Ends?"