The requirement that a property applying for a Boiler Upgrade Scheme (BUS) grant must have no outstanding loft and cavity wall insulation recommendations on its Energy Performance Certificate (EPC) was removed on 8 May 20241. The change was one of a set of amendments to the scheme that came into force on that date, following a consultation by the previous government2. The Department for Energy Security and Net Zero (DESNZ) had told the Committee of Public Accounts that it would remove the requirement in May 2024, "which duly happened on 8 May"3.
The BUS is an England and Wales scheme that came into force on 1 April 2022 and is administered by Ofgem1. It provides upfront capital grants towards heat pumps and, in limited circumstances, biomass boilers, and is installer-led: the installer submits a voucher application on behalf of the property owner1. Current grant values are £7,500 towards an air-to-water heat pump, £7,500 towards a ground source heat pump, £2,500 towards an air-to-air heat pump, £5,000 towards a biomass boiler, and £9,000 towards an air-to-water or ground source heat pump for eligible off-gas grid properties heated by LPG or oil1.
The 8 May 2024 changes also included confirmation of the scheme's extension to 2028, the introduction of a 120-day limit after commissioning for submitting a redemption application, and expansion of support to biomass boilers that can provide a cooking function2. Ofgem described the insulation change as the "removal of the requirement to install loft or cavity wall insulation if recommended on the property's EPC"2.
"DESNZ told us that it would be removing this requirement in May 2024, which duly happened on 8 May"
The committee said DESNZ was leaving insulation as a choice for householders but had not made available additional evidence about how that choice would affect energy bills3. It recommended that DESNZ set out how it would make the heat pump landscape easier to navigate, including comparing heat pump running costs in homes with and without insulation3. Nesta, which has researched public perceptions of the scheme, listed "the restriction of no outstanding recommendation for loft and cavity wall insulation being removed in May 2024" among the scheme's changes5.
Why it matters for households
Before 8 May 2024, an EPC recommending loft or cavity wall insulation could block a BUS application until the work was done. Removing that condition separates the grant decision from the insulation recommendation, so a home's insulation and glazing state no longer gates access to the Boiler Upgrade Scheme grant on that specific ground1.
The practical effect is that a household can now receive the grant without first carrying out recommended loft or cavity wall insulation. The committee noted that no additional evidence was published on how that choice affects energy bills, and that households may face complexity in deciding whether insulation upgrades are needed to manage bills3. Insulation remains relevant to how much energy a home uses and how well a heat pump performs, but it is no longer a condition of BUS eligibility on EPC grounds1.
What happens next
The scheme's later changes are dated in the published record: updates to Permitted Development Rights on 29 May 2025, further eligibility and process changes on 28 April 2026, and a £9,000 off-gas grid grant route from 21 July 20261. Funding was confirmed up to 2029/30 through the Warm Homes Plan in January 20261. The next BUS statistics are due for publication on 24 September 20261.
Sources5 cited
- [](https://assets.publishing.service.gov.uk/media/6a855be254bcee010d5144fa/Boiler_Upgrade_Scheme_BUS_Statistics_July_2026.xlsx), assets.publishing.service.gov.uk
- BUS Annual Report 2024 to 2025, ofgem.gov.uk
- Decarbonising home heating, committees.parliament.uk
- Decarbonising home heating - Committee of Public Accounts, publications.parliament.uk
- Understanding public perceptions of the Boiler Upgrade Scheme | Nesta, nesta.org.uk