How Much Does a Ground Source Heat Pump Cost in the UK & How Much Can You Save?

So, upgrading insulation can make sense – albeit this comes with its own costs and considerations. If the load is calculated at, say, 12kW, then your installer might specify a 13kW ground source heat pump. “One factor with the kit price is whether the heat pump needs a single-phase or three-phase electrical supply,” says David Billingsley, sales director at UK-based GSHP manufacturer, Kensa. “Most of the properties we deal with in the UK are single-phase.”

A straight pipe collector loop system being laid in trenches as part of an installation by Green Building Renewables

The ground source heat pump will be powered by a collector buried in the earth. This should be specifically designed to provide sufficient energy throughout the year to satisfy your home’s annual heat demand (different to the peak load).

It can be either a horizontal ground loop (such as coiled slinky pipework) or a vertical borehole. Quality design is crucial here: your supplier should be looking to specify the most cost-effective heat pump solution for the ground conditions.

Size matters with any heating system, but particularly with ground source heat pumps, as a bigger output means a larger collector array, with all the associated plant and labour costs.

Here’s a rough guide to ground source heat pump costs:

• A 150m² house constructed to modern Building Regs might need a 7kW GSHP, with a total installed ground source heat pump cost (including horizontal collector loop, heat pump, hot water tank and commissioning) of around £20,000-£25,000.
• A 250m² home built to the same standard, meanwhile, might require an 11kW system at more like £25,000-£30,000. Switch to a borehole rather than horizontal loop, and those prices will rise significantly.

Which Heat Emitters Work Best with a Ground Source Heat Pump?

Heat pumps work best when delivering consistent warmth at a relatively low temperature. This makes them an ideal partner for well-insulated and airtight homes with low-temperature emitters, such as underfloor heating (UFH), although you can also pair a ground source heat pump with radiators. The key is to ensure the whole system is designed in synergy.

In a retrofit scenario, you may well need to replace some of the radiators and distribution pipework. Clearly, this will have a significant impact on your overall ground source heat pump costs; but a good installer will help you identify where savings can be made.

Photo: istock.com / adventtr

David Billingsley, sales director at UK-based GSHP manufacturer, Kensa, shares his experience installing a system and breaks down how much the ground source heat pump cost to install:

“My own home is a good example of something that, on paper, looks marginal for a GSHP,” says David Billingsley. “It’s an old cob building, which we’ve put a 70m² extension on, taking the total house size to 250m². The house extension has UFH, but in the rest of the house we stuck with radiators.”

David estimates his ground source heat pump cost around £28,000 fully installed. “If it was a new build we could have taken a few thousand off that, as we wouldn’t have been pulling out and replacing elements, paying to get rid of old kit etc.” He keeps the house at around 18°C. “This gives us the comfort level we want. We get plenty of hot water, and performance is consistent – we spend the same on our heating now as we did for oil before we extended!”

Work With a Good Installer to Keep Your Ground Source Heat Pump Cost Down

Working with a quality installer helped to keep a lid on ground source heat pump costs. “Of the 15 radiators in the main house, our installer reused seven,” says David Billingsley.

“For instance, he took a panel with decent output from our daughter’s bedroom and re-fitted it into one of the boys’ rooms. He also tried to reuse the original flow-and-return drops wherever possible – so, where there was a K1 (single-panel) radiator, he’d replace it with a K2 (double-panel) radiator in the same width to achieve the output required.”

Available in four output sizes, the NIBE S1155 is an intelligent inverter-driven ground source heat pump designed to be combined with the company’s smart home accessories to create an efficient, easy-to-control living environment

This kind of savvy approach can cut the amount of new copper pipework required in a retrofit, reducing the overall installed cost for your GSHP. However, it won’t work in every project. “Some radiators might need to be changed due to age or corrosion,” explains eco heating specialist and Build It Live expert, David Hilton.

“The infrastructure may also not be ideal – old single-pipe configurations with radiators on a single circuit aren’t suitable for heat pumps, for instance.” Similarly, small or micro bore pipes (common from the 1970s, and typically 8mm or 10mm in diameter) will increase resistance in the system. “These may need replacing to deliver the required heat, which will add significant disruption and cost,” says David Hilton.

How Will Garden Size & Collector Type Impact Ground Source Heat Pump Costs

A ground source heat pump requires a big area for its heat source. If you have a suitably large garden, the most affordable solution is generally to bury pipes in trenches about 1m-2m deep – what’s known as a horizontal loop. “The collector is the battery for your GSHP, so you’ve got to get it right,” says David Billingsley. “People might think they have a big garden, but in terms of heat pumps, it turns out not to be the case. On a typical project, you might need a 40-50m run to get a ground loop in.”

A horizontal install should be straightforward to do on a self build, where there’s easy access and you’ll have a digger on site for groundworks, but is more disruptive with existing homes. “The excavation is labour intensive, and any subsequent making good of the garden will inevitably bring significant additional cost,” says David Hilton.

Peter and Kay Babbington were keen to install low-carbon heating, and quickly decided that a ground source heat pump would fit the bill perfectly. A 9kW Kensa Evo GSHP was specified to provide space heating and hot water, alongside a solar thermal array. Long-term Kensa partner Total Renewable Solutions was appointed as the installer.

For tighter plots or where the expense of replanting would prove prohibitive, you’ll need a vertical borehole setup. This should be designed by a qualified geologist, to ensure the ground conditions can meet your home’s heat demand, and involves specialist drilling rigs on site (good access is a must for this). For an average home, the cost of vertical collectors might start from about £8,000 – but that can rise depending on size and ground conditions.

“A 9kW heat pump might typically require a 180m borehole, for instance,” says David Billingsley. “We advise customers on what’s required and can give an estimate, then we put them in touch with trusted drilling companies for a detailed quote. For my own 13kW heat pump, I have nearly 300m of borehole; although in general 260m would probably be sufficient for this size of GSHP.”

Can You Get a Grant for a Ground Source Heat Pump?

In recent years, renewable technologies have benefited from a raft of financial support. The most generous of these – the Renewable Heat Incentive – closed to new applications in 2022. It’s replacement, the Boiler Upgrade Scheme (BUS) still offers a meaningful contribution, in the form of a £7,500 grant for qualifying air source and ground source installs. “Incentives like this almost certainly won’t be available when heat pump costs drop and gas prices rise, so the BUS grant helps make early adoption appealing,” says David Hilton.

Will a Ground Source Heat Pump Cost Less to Run?

The big benefit of a GSHP is that it takes energy from a stable source (the ground). Provided the collector is properly designed, running costs will be reliable and predictable. You should see bill savings, but exactly how much depends on the quality of the install and the fuel type you’re replacing. If it’s a gas or oil boiler, running costs will be just slightly in favour of the GSHP based on current fuel prices (although you’ll make a big saving on CO2 emissions). You can expect significant savings versus LPG boilers or old-school electric storage heating.

Don’t ignore the additional benefits a GSHP can offer. “The day our oil tank disappeared, we didn’t have to worry about the look or smell anymore,” says David Billingsley. There’s also no waiting around for fuel deliveries, and almost zero ongoing maintenance – plus a ground source heat pump’s expected lifespan is twice as long as a boiler.

Ultimately, a GSHP will give you the same comfort and convenience as a boiler, with just a fraction of the carbon emissions. Plus, under the Future Homes Standard, new build houses won’t be able to connect to the gas network. As consumers get more used to life without boilers, a quality heat pump install with documented low running costs is likely to prove a real boon if you sell your home.