Ground Source Heat Pumps for Rental Properties

The short answer

A ground source heat pump makes sense for a rental when there is land to dig, or a block that can share one ground loop. For a terrace or a flat with a small yard, it is usually the wrong choice. Air source is cheaper to fit and far more common: DESNZ statistics show 99% of MCS certified retrofit heat pumps installed in January to June 2026 were air to water units.

Where it fits, ground source has real advantages for a landlord: no fan unit on the wall and steadier performance in cold weather.

When ground source suits a rented property

Ground source needs space outside and access for machinery. The Energy Saving Trust says the ground must be suitable for digging, reachable by machinery from a road entrance, and clear of trees. For a newly built three bedroom house it expects two trenches of 30 to 40 metres. Larger or less insulated homes need a bigger loop.

Where land is short, a vertical borehole can replace trenches. The Energy Saving Trust describes a borehole as about 20cm wide and between 75 and 200 metres deep, usually needing a specialist ground survey, and usually more expensive than trenches.

Rental type	Ground source fit	Why
Rural farmhouse or cottage on oil or LPG	Often good	Land for trenches, and the £9,000 grant applies where there is no mains gas
Larger detached house with a garden	Possible	Trenches or a borehole; higher heat demand suits the larger investment
Block of flats you own outright	Possible as a shared loop	One ground loop serving several flats; see the shared loop section below
Terraced house or flat with a small yard	Usually poor	No room for trenches; a borehole may be possible but costs more
Leasehold flat in someone else’s block	Rarely possible	The ground is not yours to dig

The Energy Saving Trust also notes the indoor unit, often combined with the hot water cylinder, is roughly the size of an American style fridge, about 120cm by 60cm by 60cm. In a small rental that space can matter as much as the garden.

Shared ground loops for blocks

A shared ground loop is one network of pipes in the ground serving several homes, each with its own heat pump. The Energy Saving Trust says blocks of flats can share large ground loops, usually fitted to the whole building at once, with maintenance costs built into shared service charges.

For a landlord who owns a whole block, two points matter:

• The grant. GOV.UK lists £7,500 towards a ground source heat pump, “including water source heat pumps and those on shared ground loops”. There is one grant per property.
• It is still rare. DESNZ Boiler Upgrade Scheme statistics to the end of August 2026 show 75 voucher applications for shared ground loop heat pumps, against 2,425 for standard ground source and 147,883 for air to water.

For whole-building options beyond a single loop, read heat networks and ambient loops for build to rent before scoping a whole block.

What it costs

DESNZ publishes installed costs taken from MCS certificates for Boiler Upgrade Scheme installs. For ground source heat pumps in April to June 2026:

Measure, 2026 Q2	Ground source	Air to water (for comparison)
Median installed cost	£27,232	£12,908
Lower quartile	£18,136
Upper quartile	£42,110
Median capacity	10.5kW

DESNZ notes these costs are self-reported by installers, include equipment, labour and VAT, and should include the grant value. The Energy Saving Trust (page updated 16 July 2026) gives a lower guide: “typically around £15,000” where the loop is buried in trenches, and considerably more for a borehole. The gap between the two shows how much the ground work drives the price.

Worked example (modelled, not a real project)

Inputs: the DESNZ 2026 Q2 median of £27,232, treated as the full price including the grant value; the £7,500 grant, or £9,000 where oil or LPG is replaced with no mains gas connection. The DESNZ figures are self-reported by installers, so what each cost covers can vary.

Case	Installed cost	Grant	Landlord pays
Mains gas rental	£27,232	£7,500	£19,732
Off gas rental on oil or LPG	£27,232	£9,000	£18,232

A real quote can sit well above or below this. Treat it as a scale check, not a budget.

What moves the price

• trenches or boreholes, and how easy the ground is to reach
• the size of the property and how much heat it needs
• radiator upgrades, or new underfloor heating
• the heat pump’s make, model and size

The Energy Saving Trust lists these same factors. Installing heat pumps in homes carries 0% VAT until 31 March 2027, then 5% from 1 April 2027. If the landlord is funding the balance, the Warm Homes Loan Scheme sets a ground source cap of £35,000; it is a loan from a lender, not a grant.

Disruption with tenants in situ

Ground source is the most disruptive heat pump to fit in an occupied home. Plan for:

• Ground works. Trenches or a drilling rig in the garden, with machinery access from the road. Gardens, paths and parking may be out of use for a period.
• Indoor work. A fridge-sized indoor unit, a cylinder, and often larger radiators. That means pipework in occupied rooms.
• Heating and hot water downtime. Agree in writing how the tenant will keep heat and hot water during the changeover.

Ask the installer for a written programme you can share with the tenant before you sign. Since 1 May 2026, tenancies in England are periodic, so you cannot wait for a fixed term to end; see the Renters’ Rights Act and energy upgrades. If a void period is coming up, that is the least disruptive time for ground works.

How it performs

Ground temperature changes less than air temperature, so ground source tends to hold its efficiency in cold weather. In the Electrification of Heat demonstration project, run by Energy Systems Catapult for the government, the median ground source COP at minus 5°C was 3.10, against 2.30 for air source. The report warns its ground source sample was small (23 analysed properties, 16 on shared loops) and should not be treated as a reference figure. More on this in do heat pumps work in cold weather.

When ground source is not the right answer

• Little or no land. Air source, or air to air in a small flat, will usually be far cheaper.
• A poorly insulated house. A bigger heat demand means a bigger loop and a bigger bill. Fabric work first may be the better spend.
• A short holding period. If you plan to sell within a few years, the extra £14,000 or so of median cost over air source is hard to recover.
• Hybrid systems. The grant cannot be used for a heat pump paired with a boiler.

The Boiler Upgrade Scheme rules also apply: you must own the property, the installer must be MCS certified, and the install must happen within 120 days of applying. Details are on the Boiler Upgrade Scheme for landlords page.

Next step

Compare the cost against air source for your own rental with the heat pump landlord calculator. If you want a ground source design priced, send an enquiry through the quote page and relevant independent firms contact you, with no charge to you and no obligation.

Figures were read from the sources listed on 8 October 2026. This is general information, not financial or tax advice.