Statutory Framework: How the Boiler Upgrade Scheme Operates
Administered by the Office of Gas and Electricity Markets (Ofgem) under the Boiler Upgrade Scheme (England and Wales) Regulations 2022 (SI 2022/439), BUS is the flagship consumer grant decarbonising domestic home heating.
Following statutory amendments in October 2023 that raised the capital grant from £5,000 to £7,500, consumer uptake rose by over 70% nationwide.
The scheme operates as an upfront discount, not a retrospective rebate. The Microgeneration Certification Scheme (MCS) installer applies directly to Ofgem for a grant voucher and subtracts the full £7,500 from the homeowner's quote.
| Low-Carbon Technology | Maximum Grant Award | Eligible Fuel Replacement | Statutory Voucher Validity |
|---|---|---|---|
| Air Source Heat Pump (ASHP) | £7,500 | Existing gas, oil, LPG, or electric resistance boiler | 3 Months from issue date |
| Ground Source Heat Pump (GSHP) | £7,500 | Existing gas, oil, LPG, or electric resistance boiler | 6 Months from issue date |
| Water Source Heat Pump | £7,500 | Existing fossil fuel heating | 6 Months from issue date |
| Biomass Boiler | £5,000 | Rural off-gas properties only; high emissions restrictions | 3 Months from issue date |
The Autumn Fiscal Review & Budgetary Allocation Updates
Search interest around 'boiler upgrade scheme budget reduction' erupted following central government budget re-allocations across Department for Energy Security and Net Zero (DESNZ) capital budgets.
Key regulatory realities for applicants:
• Scheme Longevity Confirmed: The Boiler Upgrade Scheme remains legally ringfenced with statutory funding secured through to 2028 under the Warm Homes Plan framework.
• Monthly Allocation Limits: To prevent annual voucher budget exhaustion during peak winter installation periods, Ofgem maintains rolling monthly voucher caps. Installers reserve vouchers on a first-come, first-served basis upon contract signing.
• No Reduction in Per-Household Grant: The headline grant remains at £7,500 per property; individual household grant awards have not been cut.
EPC Insulation Rules: The Elimination of the Insulation Barrier
When BUS originally launched in 2022, regulations strictly required homeowners to install any cavity wall or loft insulation recommendations listed on their Energy Performance Certificate before a voucher could be paid.
Under the Boiler Upgrade Scheme (England and Wales) (Amendment) Regulations 2024, this requirement was officially abolished:
• No Mandatory Insulation Works: Homeowners are no longer forced to spend thousands of pounds on secondary insulation retrofits just to qualify for the £7,500 grant.
• EPC Still Required: You must still possess a valid Energy Performance Certificate (EPC) issued within the last 10 years, which Ofgem uses to confirm property characteristics and baseline heating type.
• EPC Exemptions: If your property is a listed building, within a conservation area, or structurally unable to receive insulation, it qualifies without obstacle.
Landlord Eligibility: Buy-to-Let and HMO Properties
Private residential landlords are fully eligible to apply for BUS grants across their rental portfolios:
• No Portfolio Caps: Landlords can claim £7,500 grants for multiple domestic properties, provided each property satisfies individual eligibility criteria.
• Houses in Multiple Occupation (HMOs): Eligible provided the property is served by a central domestic heating system capable of meeting the building's total thermal space heating and hot water demand.
• Commercial Properties: Small non-domestic buildings qualify provided the heat pump capacity does not exceed 45 kWth.