Ofgem published version 2.0 of the ECO4 Delivery Guidance and Measures Table on 14 August 2023. The version reflected changes made by part 10 of The Electricity and Gas (Energy Company Obligation) Order 2023, which applies to measures installed from 14 August 20231.
Under those first ECO4 legislative amendments, electric storage heaters and Electric Heating Systems are classed as renewable heating systems when installed in a home which has solar PV or receives solar PV as part of the same project2. The same wording appears in the summary of updates covering the version 2.0 period1.
The guidance sits within the ECO4 scheme, the supplier-funded obligation that pays for insulation and heating measures in qualifying homes. Version 2.0 was one of a series of updates to the document. Ofgem's summary of updates records the following publication dates for the delivery guidance:
| Version | Publication date |
|---|---|
| 1.0 | 14 October 2022 |
| 1.1 | 3 February 2023 |
| 2.0 | 14 August 2023 |
| 2.1 | 5 April 2024 |
| 3.0 | 7 August 2025 |
| 3.1 | 10 October 2025 |
| 3.2 | 8 December 2025 |
| 4.0 | 26 March 2026 |
The dates are given in Ofgem's summary of updates to the ECO4 delivery guidance and measures table2. Later versions of the guidance addressed matters including the treatment of Working Tax Credit and Child Tax Credit as eligible benefits, rural area definitions, solar PV requirements and the extension of ECO4 by nine months to 31 December 20262.
The Energy Company Obligation is delivered by suppliers and their installers, with scheme delivery handled through approved routes. Further detail on how the obligation operates is set out in the grants and schemes section.
Why it matters for households
The 14 August 2023 change affected what could count as a renewable heating system under ECO4. Electric storage heaters and Electric Heating Systems installed in a home with solar PV, or where solar PV was installed as part of the same project, were classed as renewable heating systems from that date2. That classification matters because it determines whether a particular heating measure is eligible for funding under the scheme, and therefore whether a household could have that work paid for through the obligation rather than privately.
The guidance also sets the rules installers and suppliers must follow when evidencing eligibility, assessing a property and completing work. Changes to those rules can affect whether a home qualifies, what evidence is accepted and how a project is recorded. The version 2.0 document applied to measures installed from 14 August 2023, so homes where work was carried out from that date fell under the amended rules1.
What happens next
Ofgem's summary of updates records subsequent versions of the delivery guidance, including version 2.1 on 5 April 2024, version 3.0 on 7 August 2025, version 3.1 on 10 October 2025, version 3.2 on 8 December 2025 and version 4.0 on 26 March 20262. Version 4.0 reflected the extension of ECO4 by nine months to 31 December 20262. The summary also records that the Great British Insulation Scheme closed on 31 March 20262.