Boiler Upgrade Scheme 2026 (GB)

The Boiler Upgrade Scheme (BUS), administered by Ofgem on behalf of the Department for Energy Security and Net Zero (DESNZ, formerly BEIS), provides upfront capital grants to property owners in England and Wales who replace existing fossil fuel heating systems with eligible low-carbon alternatives. For architects and building designers, understanding the BUS is increasingly important when advising clients on specification choices during both new-build and retrofit projects.

Eligibility is open to owner-occupiers, landlords, and small non-domestic properties in England and Wales. The property must have a valid Energy Performance Certificate (EPC) with no outstanding recommendations for loft or cavity wall insulation — ensuring the building fabric is adequately prepared before a low-carbon heating system is installed. Social housing and new-build properties (those without a pre-existing heating system) are generally excluded from the scheme.

The grant values as of 2026 stand at £7,500 for air source heat pumps (ASHPs) and ground source heat pumps (GSHPs), and £5,000 for biomass boilers. These grants are paid directly to the MCS-certified installer, who deducts the amount from the customer's invoice — meaning the homeowner or building owner never handles the grant funds directly. Only installers registered under the Microgeneration Certification Scheme (MCS) are permitted to apply on behalf of clients.

To facilitate a BUS installation, architects should ensure their designs accommodate the necessary infrastructure: sufficient external space for an ASHP unit or ground collector arrays for GSHPs, appropriate internal space for the heat pump cylinder and controls, and adequate insulation standards to maximise system efficiency. Once the installer is engaged, they submit the grant application via the Ofgem BUS portal. The property owner must give permission for the application and confirm eligibility. Vouchers are issued and must be redeemed within three months of issue.

Note: This article is not a substitute for legal or professional advice. Please consult a qualified expert for advice specific to your project or circumstances.

Umsetzungs-Checkliste

1. Confirm the property is in England or Wales and has an existing fossil fuel heating system
2. Obtain a current EPC and check for any outstanding insulation recommendations — address these before applying
3. Select an MCS-certified heat pump or biomass boiler installer
4. Ensure the building design provides adequate space for the chosen low-carbon heating system
5. Instruct the installer to submit the BUS grant application via the Ofgem portal
6. Receive and redeem the grant voucher within the 3-month validity window
7. Retain documentation (EPC, installer certificates, invoices) for compliance records