What a commercial heat pump costs after grants and tax relief

There is no single sticker price for a commercial heat pump, and any installer who quotes one before seeing your building is guessing. Cost is driven by the building's peak heat load, the technology you choose, the emitter upgrades the design needs, and whether your electricity supply has the capacity to take the extra load. What this guide sets out is the typical range, and an honest explanation of what moves the number up and down.

As a broad guide, a commercial air-source system typically runs from around £60,000 to £600,000. Ground-source sits higher, roughly £150,000 to £2 million and beyond, because of the borehole drilling or ground loops. A hybrid boiler-replacement retrofit, where the heat pump covers most of the load and a peaking boiler handles the coldest days, usually lands between £70,000 and £500,000. High-temperature process and industrial systems and full heat networks run higher again, into the millions. The cards below break these ranges down by system type.

What actually drives the cost

The starting point is always the building's peak heat-loss and its annual heat demand, not its floor area. Two buildings of the same size can need very different heat pumps depending on fabric, glazing, occupancy hours, and the temperature the heating system has to deliver. That is why a good installer will carry out a heat-loss survey and review at least twelve months of gas or oil consumption before putting a figure in front of you.

The second big driver is your existing emitters. Most commercial radiator and pipework systems were sized for a gas boiler running at 70 to 80C. Heat pumps run most efficiently at lower flow temperatures, typically 45 to 55C, so the emitters sometimes need upgrading to deliver the same heat at a lower temperature. A good installer surveys the existing system first, and in many buildings selective upgrades are enough rather than a full strip-out. Where high flow temperatures are genuinely unavoidable, a high-temperature heat pump or a hybrid design avoids the cost of re-emittering the whole building.

The third, and the one most often missed, is your electrical supply. A large heat pump adds meaningful electrical load. If the existing supply cannot take it, a Distribution Network Operator (DNO) supply upgrade may be needed, and that is frequently the longest-lead and one of the more expensive items in the whole project. Ask the installer to confirm available capacity at the feasibility stage so it is never a nasty surprise later. On constrained sites, options include phasing, hybrid designs, or demand management to stay within the supply you already have.

Running cost: the honest version

The capital cost is only half the picture, and the running-cost question is where most buyers have been let down before. Electricity currently costs around three to four times as much per unit as gas, so a heat pump only saves money if it is efficient. The figure that matters is the SCOP, the seasonal coefficient of performance, measured to BS EN 14825. A SCOP of 3.5 means the system delivers 3.5 units of heat for every unit of electricity it draws, which offsets most of the gap between electricity and gas unit prices.

Running cost should be modelled from your actual consumption data at current and forecast prices, not from a brochure, so ask the installer to do this. With low flow temperatures and a sensible electricity tariff, a well-designed commercial heat pump is at or below gas running cost today in many buildings, and the gap improves every year as gas carbon levies rise and the electricity grid decarbonises. Where the numbers are marginal, a good installer will say so, and a hybrid design is often the answer.

Payback, and how to measure it

Simple payback, the capital cost divided by the annual saving, is the figure most people ask for, and across the system types covered here it typically falls between roughly 7 and 14 years depending on technology and how much grant support the project attracts. But simple payback ignores the time value of money and the rising cost of gas, so for any serious business case it is worth also modelling the internal rate of return (IRR) and net present value (NPV) over the system's life, alongside the carbon saving for your net-zero and Scope 1 reporting. A heat pump removes on-site combustion entirely, so its only emissions come from grid electricity, which keeps falling.

Tax relief brings the net cost down

The Annual Investment Allowance and other capital allowances (AIA, £1m a year) are tax reliefs on qualifying plant and machinery, and a heat pump installation may qualify. Relief applies to the cost the business itself funds, so any grant reduces the qualifying spend. Treatment of ancillary works such as wiring can differ, so always confirm it with your accountant; the official detail is in the government's capital allowances guidance. Grant funding is narrower: the Boiler Upgrade Scheme can cover small non-domestic systems up to 45 kWth, while the other main schemes are closed or limited to particular bodies, as set out on our grants and funding page.

The costs people forget

A realistic budget includes more than the heat pump itself. Expect to account for the heat-loss and emitter survey, any emitter or pipework upgrades, a buffer vessel and hydraulic separation, controls and the bivalent changeover strategy on hybrid systems, plant-room or external compound works, a BS 4142 acoustic assessment for external air-source units, F-Gas compliant refrigerant work, and potentially a DNO supply upgrade. Ground-source adds ground investigation and drilling. Ask the installer to itemise all of this in the written quote so there are no mid-project add-ons.

Timeline and cash flow

An air-source retrofit is typically four to twelve weeks on site once design and any DNO work are agreed, and the live boiler cutover is usually a matter of hours rather than days. Ground-source takes longer because of the drilling and ground works, often several months. Industrial and heat-network schemes run to twelve months or more. A good installer plans the changeover around your operating calendar, never a peak-heat week, and on retrofits keeps the existing boiler live as backup through commissioning so you are never without heat. To get a figure specific to your building, the fastest route is to send an enquiry after which the installer can review your consumption data and survey the building.