The Department for Energy Security and Net Zero (DESNZ) consulted in August 2025 on proposals to extend the ECO4 end date, according to the Household Energy Efficiency statistical release published in February 20261. The policy decision is that ECO4 will be extended by nine months, to 31 December 20261. The consultation was set out in a document titled Extending the ECO4 end date: consultation document1.
The statistics in that release cover measures installed up to December 2025, so they do not yet show any effect of the extension1. Under ECO4, just over 1 million measures had been installed in around 298,000 households by the end of December 2025, including measures installed since the obligation began in April 2022 and measures carried over from earlier phases1. Across all phases of the Energy Company Obligation, around 4.4 million measures have been installed in 2.6 million households1.
Delivery in the most recent quarter was lower than the quarter before. Around 63,100 measures were installed in Q4 (October to December) 2025, a 16 per cent decrease compared with Q3 (July to September) 2025, but a similar level to Q2 (April to June) 20251. In December 2025, 16,800 measures were delivered, a 25 per cent decrease from 22,300 in November1. The release notes that this was a similar decrease to the one between November 2024 and December 2024, which was 30 per cent1.
The mix of measures under ECO4 has shifted towards heating rather than insulation. To the end of Q4 2025, measures categorised as other heating, which covers heating controls, electric storage heating and district heating, represented 50 per cent of ECO4 measures installed, of which 97 per cent were heating controls1. Loft insulation followed at 14 per cent1. Heating controls alone account for 49 per cent of all ECO4 measures1. The share of insulation measures has fallen from 67 per cent in ECO1 and ECO2 to 29 per cent in ECO41.
| ECO4 measure group | Share of ECO4 measures, to end December 2025 |
|---|---|
| Other heating (mainly heating controls) | 50% |
| Loft insulation | 14% |
| Micro-generation | 11% |
| Boilers | 10% |
Source: Household Energy Efficiency statistical release, February 20261
To the end of December 2025, the total estimated annual bill savings from measures installed under the ECO4 obligation were £210.5m1. Under ECO4, 24,100 measures were delivered through Flexible Eligibility in Q4 2025, which was 38 per cent of all measures installed in that quarter1. The release states that the number of Flexible Eligibility measures installed in December 2025 was 4,400, the lowest since August 2023, and that these figures are provisional and subject to revision1.
Why it matters for households
ECO4 is the mechanism through which energy suppliers fund efficiency and heating measures in qualifying homes, so its end date sets the window in which work can be commissioned and completed. Extending the obligation to 31 December 2026 keeps that window open for a further nine months beyond the original date, which matters for households part-way through a whole-house package, where insulation must often be installed before heating measures1.
The published figures show what the scheme has delivered so far and where it has concentrated. Heating controls, rather than fabric measures, make up the largest single share of ECO4 delivery, and the average number of measures per household under ECO4 is 3.39 including carried-over actions, against 1.45 at the end of ECO31. That reflects the scheme's multiple-measure approach, in which a single home may receive several measures in one assessment1.
For a household, the practical effect of the extension is that the scheme's rules and eligibility routes, including Flexible Eligibility through local authorities, continue to apply for longer. The statistics do not report how the extension will be funded, whether supplier targets change, or what the position is for households in Scotland and Wales, where delivery and policy responsibilities differ. Those points have not been reported in the release.
What happens next
The next headline release on the gov.uk website is planned for publication at 9.30am on 26 March 2026 and will contain the latest available information on headline ECO measures up to the end of January 20261. The release also notes that the December 2025 Flexible Eligibility figures are provisional and may be revised when the next set of statistics is released in March 20261.
Sources1 cited
- Household Energy Efficiency statistical release February 2026, assets.publishing.service.gov.uk