On 14 March 2024, Claire Coutinho, Secretary of State for Energy Security and Net Zero, announced updates to the Boiler Upgrade Scheme (BUS) and the Clean Heat Market Mechanism (CHMM), including changes relating to biomass technologies1. The announcement was reported by HETAS, an independent certification body1.
The BUS provides upfront capital grants for the installation of heat pumps and biomass boilers in homes and non-domestic buildings in England and Wales. Installers apply on behalf of property owners. The grant amounts are £7,500 off the cost and installation of an air source heat pump, £7,500 off a ground source heat pump including water source heat pumps, and £5,000 off a biomass boiler1. £450 million of grant funding is available over three years from 2022 to 20251.
The government said it will make four changes1:
| Change | Detail |
|---|---|
| EPC insulation recommendations | Remove the requirement for a property to have no outstanding Energy Performance Certificate recommendations for loft and cavity wall insulation |
| Shared ground loops | Increase the capacity limit from 45kW to 300kW |
| Biomass definition | Expand the definition of eligible biomass boilers to include those with a cooking function, provided it is integrated and cannot be controlled separately to the property's heating function |
| Grant levels | Introduce flexibility into the regulations to vary grant levels more quickly for specific types of property if needed in response to changing market conditions or future regulation |
On the EPC change, the government said its guidance remains that properties should be appropriately insulated, and that the change addresses concerns about forcing hard-pressed families to carry out insulation upgrades to be eligible, instead empowering them to decide what is right for them1. On shared ground loops, it said the change addresses concerns that the cost of groundworks is a significant barrier to deployment, and will spread the costs of ground infrastructure1.
Eligibility rules for biomass appliances on the BUS include off-gas-grid properties in rural locations and confirmation that the boiler meets maximum emission limits for particulate matter and NOx. In most cases the product must be certified under the MCS Biomass Standard, which includes biomass boilers with integrated cooking functions1. HETAS Head of Technical Calvin May said:
"HETAS welcomes the changes to the Boiler Upgrade Scheme for biomass appliances, allowing a wider range of appliances to become eligible. Biomass can be the heat source of choice for many off-grid properties and such appliances can provide a range of benefits to home heat."
At the same time, the government published its response to the consultation on improving boiler standards and efficiency. It plans to implement most proposals via an update to ecodesign and energy labelling regulations, which would apply in Great Britain1.
Why it matters for households
For homes off the gas grid, particularly in rural areas, the biomass changes widen the range of appliances that can attract the £5,000 grant, including models that also cook. Households considering a heat pump may find the removal of the EPC insulation precondition relevant, since outstanding loft or cavity wall insulation recommendations will no longer block an application, although government guidance still states properties should be appropriately insulated. The shared ground loop change raises the capacity ceiling from 45kW to 300kW, which relates to the ground infrastructure costs that can be shared across properties. The grant amounts themselves are unchanged in this announcement. The government has also signalled it wants the ability to vary grant levels more quickly for specific property types, which means future grant values could change at shorter notice than before.
What happens next
The government intends to publish a consultation on draft legislation to give effect to these proposals in due course1. No date for that consultation has been reported.
Sources1 cited
- Changes to the Boiler Upgrade Scheme - HETAS, hetas.co.uk