BUS Grant Annual Review: Uptake, Trends, and Gaps

The Boiler Upgrade Scheme is the engine driving UK heat pump adoption. Since its launch in May 2022, it has supported hundreds of thousands of installations with £7,500 grants. But how effectively is the money being spent? Where are the gaps? And what needs to change to accelerate uptake? This annual review analyses the scheme's performance using data from Ofgem and DESNZ.

The BUS grant has proven to be the most effective policy instrument for driving heat pump adoption in the UK. It accounts for approximately 70% of all domestic heat pump installations, confirming that financial support is the primary enabler for most homeowners. For eligibility details, see our grant eligibility checker and comprehensive grants guide.

Scheme Overview

Uptake Data and Trends

The increase from £5,000 to £7,500 in October 2023 was transformative. Applications surged immediately and have remained at elevated levels. The higher grant brings the out-of-pocket cost for a typical installation to £3,500-£6,000 — comparable to a mid-range gas boiler installation and dramatically reducing the financial barrier.

Regional Distribution

Scotland is not included as it operates its own grant scheme through Home Energy Scotland.

The regional disparity reflects several factors: off-gas-grid homes (more common in the South West and East) have stronger financial incentives to switch, installer availability varies significantly, and awareness levels differ. London's low uptake reflects the predominance of flats and gas-connected homes. For county-level data, see our interactive county map.

Technology Split

Air source heat pumps dominate BUS grant applications, reflecting their lower cost, simpler installation, and suitability for a wider range of properties. Ground source systems, while more expensive upfront, offer higher efficiency and may be preferred for larger rural properties.

Spending Analysis

The BUS grant has been cost-effective compared to other decarbonisation measures. At £7,500 per installation, each grant supports a carbon reduction of approximately 1.5-3.0 tonnes of CO2 per year, delivering a cost per tonne of CO2 saved of approximately £100-£180 — competitive with most other decarbonisation interventions.

Total scheme spending to date is estimated at £2.5-3.0 billion. The economic multiplier effect — every £1 of grant generates approximately £2 of private spending on equipment and installation — makes it one of the most effective uses of public money for climate action.

Common Application Issues

Despite improvements, some applications still face problems:

• EPC issues (35% of rejections): Outstanding insulation recommendations not addressed. Solution: get your EPC early and address any issues
• Documentation gaps (25%): Incomplete installer paperwork. Solution: use experienced MCS installers
• Ineligible properties (20%): New-builds, commercial properties, or homes already on RHI. Solution: check eligibility first with our checker
• Installer certification issues (15%): Non-MCS-certified equipment or installers. Solution: always verify MCS certification
• Other (5%): Duplicate applications, withdrawn applications, etc.

Scheme Impact Assessment

The BUS grant has demonstrably:

• Driven approximately 70% of all UK heat pump installations
• Reduced average out-of-pocket costs from £12,000 to £4,500
• Supported the growth of the MCS installer network
• Generated approximately £6-7 billion in total market activity (grant + private spending)
• Contributed to approximately 500,000+ tonnes of annual CO2 reduction

Gaps and Recommendations

Despite its success, the BUS scheme has notable gaps:

1. No support for low-income homeowners beyond ECO4 — the BUS grant requires significant out-of-pocket spending that lower-income households cannot afford
2. Regional inequity — areas with fewer installers and less awareness receive disproportionately fewer grants
3. Post-2028 uncertainty — the lack of confirmed support beyond 2028 creates hesitation among consumers and investors
4. No retrofit insulation linkage — the BUS grant does not incentivise insulation improvements alongside the heat pump

Recommended improvements include extending the scheme beyond 2028, introducing an enhanced grant for low-income households, linking the grant to insulation requirements (rewarding better-insulated homes), and increasing marketing to underserved regions.

Future Outlook

The BUS grant is confirmed until March 2028. Beyond that, the landscape is uncertain but likely to evolve in one of several directions:

• Scheme extension — most likely in some form, potentially at a reduced grant level as market maturity increases
• Transition to low-interest loans — replacing grants with government-backed green lending
• Integration with Clean Heat Market Mechanism — manufacturer obligations may reduce the need for consumer grants
• Means-tested approach — targeting grants at lower-income households while market forces drive adoption among higher earners

For homeowners, the message is clear: the current £7,500 grant is historically generous and may not last at this level. If you are considering a heat pump, acting while the full grant is available makes financial sense. Pairing with solar panels further improves the economics.

Frequently Asked Questions

How many BUS grants have been awarded?

Approximately 350,000-400,000 since launch, with ~175,000 in 2025 alone.

Is the budget being fully spent?

Approximately 90% utilisation in 2025, up from ~25% in the scheme's first year.

Which regions receive the most grants?

South West, South East, and East of England lead per capita. London has the lowest uptake.

What are common rejection reasons?

EPC issues (35%), documentation gaps (25%), ineligible properties (20%), and certification issues (15%).

Will the BUS grant continue after 2028?

Not yet confirmed. Industry expects some form of support to continue but details are unknown.