What's New: Exhaust Air, Budget & Uptake
In 2025 the Boiler Upgrade Scheme (BUS) was expanded to include more technologies. Exhaust air heat pumps are now eligible for support—a category not covered in earlier BUS guidance. The scheme also added £2,500 grants for air-to-air heat pumps and heat batteries (heat batteries once standards are in place), plus more flexibility for heat pumps combined with other electric heating.
For the main £7,500 ASHP and GSHP grants, see BUS grants now £7,500. For air-to-air MCS certification and evidence requirements, see Air-to-air heat pumps coming to MCS.
Budget and Record Uptake
The BUS budget for 2025/26 was set at £295 million, with permission to over-allocate vouchers up to £280 million so grants stay available. Heat pump adoption has accelerated: over 80,000 units were sold in 2024—a record and a 51% increase on the previous year—and since the scheme opened in May 2022 there have been over 100,000 BUS applications, with thousands of applications each month in late 2025.
DESNZ now publishes BUS statistics as official statistics, and quarterly heat pump deployment data is available on GOV.UK.
Why Surveys Still Matter
Whether the job is ASHP, air-to-air, or exhaust air, site assessment and evidence matter for BUS eligibility and MCS sign-off. Vertex provides ASHP surveys, heat loss calculations, and solar PV surveys that feed into installer workflows and MCS evidence packs.