Ofgem, the scheme administrator of ECO4 and the Great British Insulation Scheme (GBIS), opened a consultation on 7 April 2025 on how it proposes to administer mid-scheme changes to both schemes1. The changes themselves follow a government mid-scheme consultation, with the Department for Energy Security and Net Zero (DESNZ) publishing its response on 7 April 20251.
Ofgem received 18 responses in total, including from 9 suppliers, 5 installers and 4 from related industry bodies and consumers1. The decision-making process ran in three stages1:
| Date | Stage |
|---|---|
| 07/04/2025 | Stage 1: Consultation open |
| 12/05/2025 | Stage 2: Deadline for responses, consultation closed |
| 26/06/2025 | Stage 3: Consultation decision published |
On multiple insulation measures under GBIS, 16 responses addressed the question and 12 agreed with Ofgem's proposed approach1. Ofgem confirmed that secondary insulation must be promoted by the same supplier as the first insulation measure, and that a second insulation measure promoted by a different supplier from the first will be ineligible and face rejection1. Both insulation measures must take place in the same retrofit1. Ofgem stated that from 14 November 2024 they can both be installed together, but a third insulation measure could not1.
On smart thermostats, Ofgem decided that only smart thermostats completed on or after 14 November 2024 are eligible to be notified as smart thermostat measures1. The requirements include automation and optimisation in addition to some form of wider connectivity to enable remote control of the central heating system, and smart thermostats will only be eligible for a score where the specific product is listed in the PCDB for use with the heat source of the home where it is installed1. Suppliers are now able to notify the measure to Ofgem, but measures will remain with 'On Hold' status until the legislative changes come into effect1.
On rural area definitions, the Scottish Urban Rural Classification 2022 was published by the Scottish Government in December 2024, the 2021 Rural Urban Classification for England and Wales was published by ONS in March 2025, and the ONS Postcode Directory included England and Wales data in May 20251. The draft legislative amendment laid on 11 June 2025 requires changes, and Ofgem alerted suppliers with an update by email on 13 June 20251. Ofgem also confirmed that annual targets will not be removed1.
"We received 18 responses to the consultation in total"
Why it matters for households
ECO4 and GBIS are the two main routes by which energy suppliers fund insulation and heating measures in homes, so how Ofgem administers them shapes what work can be delivered and claimed. The decision that a second insulation measure must be promoted by the same supplier as the first, and installed in the same retrofit, affects whether a household can add a further measure to a project already under way. The smart thermostat rules set out what equipment qualifies and when, with eligibility tied to completion on or after 14 November 2024 and to the product being listed in the PCDB for the home's heat source. The comparison of GBIS and ECO4 sets out how the two schemes differ in scope and eligibility.
What happens next
Final guidance will be published in due course, according to Ofgem1. Measures notified under the new arrangements will remain with 'On Hold' status until the legislative changes come into effect1. The draft legislative amendment was laid on 11 June 20251. The wider process by which such rules are proposed, decided and changed is set out in energy consultations.