The Department for Energy Security and Net Zero published the final findings from the evaluation of the Boiler Upgrade Scheme (BUS) on 24 September 2026, alongside survey data tables1. The publication applies to England and Wales1.
The BUS "supports the decarbonisation of heating in domestic properties by incentivising the deployment of low carbon heating systems", according to the department, and the scheme's original duration, 2022 to 2025, is subject to an evaluation1. This is the final publication of the BUS evaluation, following a first interim report published in 2025 and a second published earlier in 20261.
The final output comprises a 98 page final report, a 132 page technical report, Wave 4 property owner survey data tables and Wave 2 property owner follow up survey data tables, the latter covering owners who had installed a low carbon heating system using the grant1. Topics covered include property owners' experiences of participating in the BUS, their satisfaction with their low carbon heating systems after one heating season, and whether they experienced changes in bills and energy tariffs1. The evaluation also covers participation in the BUS by installer companies, the impact of the scheme on low carbon heating installations, employment and wider sectoral impacts, and value for money1.
"This is the final publication of the BUS evaluation, following the first interim report published in 2025 and the second published earlier in 2026."
The published documents are the final report, the final technical report, the Wave 4 property owner survey data tables in spreadsheet and alternative formats, and the Wave 2 property owner follow up survey data tables in spreadsheet and alternative formats1. The department notes that some files may not be suitable for users of assistive technology and offers an accessible format on request1. The specific findings of the reports, including any figures on bill changes, satisfaction levels or value for money, have not been reported in the publication page itself1.
Why it matters for households
The BUS is the main grant route for households in England and Wales replacing a fossil fuel heating system with a heat pump or biomass boiler, and the grant amount and eligibility rules shape what a home can claim. The evaluation's coverage of whether participants saw changes in bills and energy tariffs speaks directly to the running cost question that sits alongside the upfront cost of a heat pump with the BUS grant. Its findings on satisfaction after one heating season, and on installer participation, bear on how the scheme has worked in practice for the homes that have used it. For households weighing a gas boiler against a low carbon system, or comparing the BUS with ECO4, the final evaluation is the fullest official account of the scheme's first phase. The scheme's statistics remain the reference point for vouchers, applications and uptake.
What happens next
The evaluation is now complete, with this final publication following the two earlier interim reports1. No further steps are set out in the publication1.