Ofgem published version 2.1 of the ECO4 Delivery Guidance and Measures Table on 5 April 20241. The version contains general formatting and drafting improvements alongside specific updates1.
On customer contributions, a section was added at paragraphs 4.24 to 4.27 covering a new requirement to collect the amount of customer contribution toward the installation of measures1. On insulation, paragraphs 5.58 to 5.96 add information and clarity on demonstrating that the insulation preconditions are met, including a new section on the 15 Year Simple Payback1. For loft insulation, paragraph 5.27 adds that signed declarations "should be present in all loft spaces, where a property has multiple", and paragraph 5.30 gives additional guidance on when loft insulation is found to be present1.
The version also covers electric heating and hybrid systems. Paragraphs 5.155 to 5.161 add information and clarity on the definition of electric storage heaters and Electric Heating Systems and the circumstances in which they can be installed1. Paragraphs 5.151 and 5.152 add wording on the definition of hybrid heat pumps and their installation1. On the measures table, Table 9 was updated to improve accessibility and reflect updates to measures eligible under certain conditions, with a row added to differentiate guidance on ESH upgrades to an HHR electric storage heater in homes with and without solar PV1.
Other changes in version 2.1 include clarification of the two processes, EER and EST Data Matching, for cross checking a person's benefit status with DWP to confirm Home Heating Cost Reduction Obligation (HTHG) membership at paragraphs 3.134 to 3.145, and additional information and improved structure of the guidance on child benefit and evidencing income thresholds at paragraphs 3.146 to 3.1651. Amendments were made to Table 14 on evidencing a gas connection, including removal of the need to evidence the property was connected on the start day of the ECO4 project, the day of the pre-retrofit assessment1. Rules around signature application were expanded at paragraphs 8.36 to 8.48, with additional clarity on acceptable and unacceptable signature practices relating to copy and pasting1. References to "new buildings" were changed to "new domestic premises" throughout1. References to electric boilers were removed throughout the document and as an acceptable post-main heat source from Table 221.
Ofgem's summary of updates records later versions of the guidance. Version 3.0 was published 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 20261. Version 4.0 reflects the extension of ECO4 by nine months to 31 December 20261. The same document states that the Great British Insulation Scheme closed on 31 March 20261.
Why it matters for households
ECO4 is the current Energy Company Obligation scheme, under which energy suppliers fund efficiency and heating measures in qualifying homes. The version 2.1 changes bear on what a household may be asked to pay towards an installation, since the guidance introduced a requirement to collect the amount of any customer contribution1. They also bear on what must be demonstrated before certain insulation measures can proceed, through the insulation preconditions and the 15 Year Simple Payback section1. For homes with electric storage heaters or Electric Heating Systems, the added definitional clarity sets out the circumstances in which those products can be installed1. The measures table row on ESH upgrades distinguishes homes with solar PV from those without1. For a household's energy independence, these are the rules that determine whether a measure can be funded at all and on what terms, rather than the level of any grant.
What happens next
The summary of updates records subsequent versions of the guidance, up to version 4.0 published on 26 March 2026, which reflects the extension of ECO4 to 31 December 20261. No further dated steps beyond those versions are set out in the published summary.