Commercial heat pump grants, mapped to the funding your building actually qualifies for
Commercial heat pump grants are the single most misunderstood part of decarbonising a non-domestic building, and that confusion costs organisations real money. The headline £7,500 Boiler Upgrade Scheme that everyone has heard of is not limited to homes: small non-domestic buildings can qualify, but it is a flat grant per installation up to 45 kWth, so it suits small systems and not building-scale plant. That leaves a lot of facilities, estates and energy managers unsure what funding exists for larger plant. Other routes have different rules, and most are now closed or narrowly targeted, and the trick is matching your building, your sector and your tax position to the right route before you commit a penny of capital. That is what this page is built around: leading with the funding question, then explaining how a system should be sized and specified so that it can qualify.
The case for acting is straightforward. Heat is roughly a third of UK carbon emissions and the gas boiler is usually the single largest source in a commercial building. Gas prices remain volatile and the Climate Change Levy adds cost on top, so heating budgets swing unpredictably year to year, while ageing boiler plant nearing failure forces the decision anyway and landlords face MEES and EPC pressure. A commercial heat pump replaces on-site combustion with electrified heat at an SCOP of typically 3.0 to 4.0 for air-source and often above 4.0 for ground-source, meaning three to four units of heat for every unit of electricity. Funding routes, where one is open to you, reduce the capital that has to be recovered, which is why checking the funding position comes first.
The funding landscape for commercial heat pumps
There is no single headline commercial grant for building-scale plant, and the larger routes are now closed to new bids, so check each on gov.uk before planning around it. Small systems may qualify for the Boiler Upgrade Scheme. Public-sector bodies such as NHS trusts, schools, colleges, universities, local authorities and emergency services used the Public Sector Decarbonisation Scheme (PSDS) for public bodies. Phase 4 closed to new applications in November 2024, there is no open application window and no confirmed successor, and funded projects continue to 2027/28. Eligible industrial sites could previously look to the Industrial Energy Transformation Fund (IETF) Phase 3, which is also closed: gov.uk lists it closed from July 2025, with no further extension or successor planned, though projects already funded continue. Heat networks and multi-building or campus schemes can look to the Green Heat Network Fund (GHNF), open to public, private and third-sector organisations (not households or sole traders) for new low-carbon heat networks and for retrofit or expansion of existing ones. Funding can be drawn down until 2029-30, but Round 12 closed on 25 September 2026, so check gov.uk for the next round.
Separately, a business can use capital tax relief. Because heat pumps are plant and machinery, full expensing is a tax relief on qualifying plant and machinery for companies. Sole traders and partnerships rely instead on the Annual Investment Allowance, which gives relief on up to £1m a year of qualifying spend. Relief applies to the cost the business itself funds, so a grant reduces the qualifying spend, and an accountant should confirm the treatment for your project. The full detail sits on our grants and funding page.
How systems should be sized and designed to qualify
Funding follows credible numbers, so the design and the grant case are the same piece of work. Sizing should never come from floor area. It should come from a proper heat-loss survey carried out by the installer and at least 12 months of your gas or oil consumption, because a competitive grant application and an honest business case both live or die on real demand data. The single biggest lever on performance is flow temperature: every degree shaved off lifts the SCOP, so a good installer designs for low flow temperatures of 45 to 55C wherever the emitters allow, and specifies to BS EN 14825 (SCOP) and BS EN 14511 (rated COP) so the performance figures in your funding bid are directly comparable to any compliant supplier.
A commercial air-source system usually lands in the 40 to 500 kW thermal band, delivered as a single unit up to a cascaded bank of 4 to 12 modular units. Ground-source runs 50 to 1,000 kW thermal on a borehole array typically 100 to 200m deep, carrying higher capital but a higher and more stable SCOP. A hybrid design pairs a 60 to 400 kW heat pump cascade with a retained or new peaking boiler, letting the heat pump carry 70 to 90% of annual load while the boiler covers the rare coldest days, often the most cost-effective retrofit because the capital ask is smaller. Ask the installer to model these side by side from your data so the chosen route is a deliberate, evidenced decision.
Costs and payback after grant (illustrative)
Installed cost is driven by technology, scale, the emitter upgrades required and any electrical supply work. As a guide, a commercial air-source project typically runs £60,000 to £600,000 with a simple payback near 8 years before any grant; ground-source £150,000 to £2,000,000 or more at a payback near 11 years before grant; and a hybrid retrofit £70,000 to £500,000 at a payback near 7 years, the shortest of the main routes. These are pre-grant figures. Where a grant such as the Boiler Upgrade Scheme (small systems) or GHNF (heat networks) applies, it meets part of the capital, and capital allowances can reduce the after-tax cost of what the business funds itself, so the effective payback can be shorter than the headline. The installer should model the full installed cost and the tax treatment together; the cost breakdown sits on our cost guide, always from your own consumption data at current and forecast prices rather than an optimistic estimate.
Compliance and sector considerations
Grant eligibility and compliance are intertwined. For systems up to 45 kWth, MCS certification (or a recognised commercial equivalent) is required to access most grant routes, so check that your installer holds it on the MCS register; above 45 kWth a good installer designs to CIBSE and BSRIA standards. All refrigerant work should be carried out by F-Gas certified engineers under the UK F-Gas Regulation, with the high-GWP phase-down steering modern units toward lower-GWP R32 (A2L) and, for higher duties, natural refrigerants such as R290, CO2 and ammonia, which carry DSEAR and ATEX siting requirements the design must address. Systems should be built to BS EN 378. Where a hybrid retains a gas boiler, Gas Safe registration is also in scope. Most air-source installs fall under permitted development but are subject to size, siting and noise limits, so a BS 4142 acoustic assessment is commonly required; listed buildings and conservation areas need consent, and ground-source open-loop systems abstracting groundwater need an Environment Agency permit. Large heat pumps add real electrical load, so DNO supply capacity should be confirmed early because a supply upgrade can be the longest-lead item, which matters acutely when a grant scheme carries a fixed completion deadline.
How to approach the funding question and the project
Start with your half-hourly meter data and 12 months of fuel consumption, and build the funding case and the engineering case in parallel rather than in sequence. Check which schemes you qualify for, and confirm with an accountant how any grant interacts with capital allowances on the spend your business funds itself. A good installer will make any DNO supply enquiry early so the long-lead item does not derail a fixed grant deadline, will survey existing emitters so you do not pay for a strip-out you do not need, and will build any application around your scheme rather than the other way round. Ask for a written quote with running cost and carbon modelled from your own data, a clear statement of the installer's warranty, and which funding or tax route the project can qualify for. Treat any quote that cannot show its working with caution.
An illustrative example
As an illustrative hypothetical example, not a real project or named client: a council-owned leisure centre with a swimming pool, sports hall and year-round heating and hot-water load on an end-of-life gas boiler might replace it with grant support, where a suitable scheme is open. The design could be a 450 kW ground-source heat pump on a borehole array, delivering heating in winter and supporting space cooling in summer, with around 1,050,000 kWh of heat a year at an SCOP near 4.1, saving roughly 190 tonnes of CO2 annually. Where a grant covers the bulk of the capital over the like-for-like boiler-replacement cost, conventional payback may not be the relevant measure, and the stable year-round SCOP plus summer free-cooling would support a net-zero strategy. The figures are illustrative and depend entirely on your building, your sector eligibility and the scheme rules in force at the time.
The right first step is to find out which funding you qualify for. Read the grants and funding routes in detail, work through the cost guide, browse the FAQs, then send an enquiry and SEO Dons Ltd will pass it to a commercial heat pump installer who can work from your meter data and the funding route that fits your building.
