Ground Source Heat Pumps (GSHP) & Costs

Ground Source Heat Pumps

Understand GSHP systems, ground loops, boreholes, installation costs and the design work required to heat your home efficiently.

Ground source heat pumps use naturally occurring heat within the ground to provide central heating and hot water.

A ground source heat pump system, commonly abbreviated to GSHP, circulates fluid through buried pipes outside the property. The fluid absorbs low-temperature heat from the ground, and the heat pump raises it to a temperature that can be used within the home.

Ground source heat pumps can supply:

Radiators.
Wet underfloor heating.
A hot-water cylinder.

Multiple heating zones.
Domestic and shared heating systems.

Unlike an air source heat pump, a GSHP does not require an external fan unit drawing heat from the outdoor air. Instead, it collects energy through horizontal pipes buried in trenches or vertical pipes installed within boreholes.

The design of the ground collector, heat pump, radiators, hot-water cylinder and controls must all be coordinated. A GSHP should therefore be approached as a complete heating and ground-engineering project rather than as a straightforward boiler replacement.

APN Boilers helps homeowners find experienced professionals capable of assessing the property, available land and complete heating system before recommending a ground source heat pump.

What Is a GSHP?

GSHP stands for ground source heat pump.

The system transfers heat from the ground into a building using a refrigeration cycle. It can produce water for central heating and heat water stored within a domestic hot-water cylinder.

A typical GSHP system includes:

A buried ground loop or borehole collector.
Water and antifreeze solution within the collector.
A circulation pump.
The ground source heat-pump unit.
A heating-water circuit.
Radiators or underfloor heating.
A hot-water cylinder.
Expansion equipment.
Heating controls.
Electrical supplies and protective equipment.

MCS defines ground source systems as heat pumps that extract energy from sources including horizontal trenches, vertical boreholes and aquifers.

How Does a Ground Source Heat Pump Work?

Buried pipework contains a mixture of water and antifreeze, often called brine or thermal transfer fluid.

This fluid circulates through the ground collector and absorbs heat from the surrounding soil or rock. The absorbed energy passes through a heat exchanger into the heat pump’s refrigerant circuit.

The heat pump then:

Evaporates the refrigerant using heat collected from the ground.
Compresses the refrigerant to raise its temperature.
Transfers the resulting heat into the building’s heating water.
Returns the refrigerant to a lower pressure so the cycle can begin again.

The heated water is circulated through radiators or underfloor heating. A separate cylinder usually stores domestic hot water for showers, baths and taps.

Ground Source or Geothermal Heat Pump?

The terms ground source heat pump and geothermal heat pump are often used to describe similar systems.

In UK domestic heating, ground source heat pump is generally the clearer term. The word geothermal is more commonly associated with naturally occurring high-temperature heat found deep underground, although it is frequently used internationally for domestic ground-loop systems.

Someone searching for a geothermal heat pump cost will normally be looking for the cost of:

A ground source heat-pump unit.
Horizontal ground loops.
Vertical boreholes.
Heating-system alterations.
Hot-water storage.
Electrical and control work.

For this page, both phrases refer to a domestic system extracting relatively low-temperature heat from the ground and upgrading it for use within the property.

Horizontal Ground Loops

A horizontal ground-loop system uses pipes buried within trenches.

The loop may consist of:

Long straight pipes.
Several parallel trenches.
Coiled or slinky-style collectors.
Multiple collector circuits connected to a manifold.

Horizontal loops can be suitable where the property has enough accessible land.

The installer and ground-loop designer should consider:

The property’s calculated heat demand.
Soil type and moisture.
Available ground area.
Trench depth and spacing.
Existing trees and roots.
Drainage and waterlogging.
Underground services.
Future extensions or landscaping.
Access for excavation machinery.
The route between the ground loop and the plant room.

Energy Saving Trust indicates that a new-build three-bedroom home might require two trenches approximately 30–40 metres long, while larger or less insulated properties may need substantially more collector area. This is only an illustration; every ground array should be designed around the site and calculated heating load.

Ground Source Heat-Pump Boreholes

Where horizontal land is limited, vertical boreholes may be used.

A specialist drilling contractor installs pipes deep into the ground. The borehole is then filled using appropriate materials to provide thermal contact with the surrounding geology and protect the ground-water environment.

Boreholes have a relatively small surface footprint but can cost significantly more than horizontal trenches.

The project may require:

A geological or thermogeological assessment.
Access for a drilling rig.
Borehole design.
Checks for mines, tunnels and underground services.
Ground-water considerations.
Environmental permits or exemptions.
Specialist grouting.
Pressure testing.
Detailed records of the completed borehole.
Reinstatement of the drilling area.

Domestic boreholes are commonly tens or hundreds of metres deep. Energy Saving Trust gives a broad range of approximately 75–200 metres, with the number and depth depending on the property’s heat demand and local geology.

Horizontal Ground Loop or Borehole?

The correct option depends on the site.

Horizontal Ground Loops May Be Better Where:

A large garden or field is available.
The ground is accessible to excavators.
Extensive landscaping disruption is acceptable.
The soil and ground conditions are suitable.
The land is unlikely to be built over later.
Installation cost needs to be controlled.

Boreholes May Be Better Where:

The available garden is limited.
The property has a substantial heating demand.
Surface disruption needs to be reduced.
The underlying geology is suitable.
Drilling machinery can reach the site.
The additional installation cost is acceptable.

Neither solution should be chosen from land area alone. The required collector capacity must be calculated and coordinated with the heat pump’s expected annual energy demand.

Shared Ground Loops

A shared ground loop can serve several properties or heat pumps.

This may be appropriate for:

Blocks of flats.
Housing developments.
Terraces.
Retirement developments.
Rural estates.
Groups of neighbouring properties.
Communal heating projects.

A central borehole or ground-loop network can supply individual heat pumps within each dwelling. This allows occupants to control their own heating while sharing the ground collector.

Shared systems require clear arrangements for:

Ownership.
Electricity consumption.
Repairs and maintenance.
Long-term responsibility.
Access rights.
Service charges.
System expansion.
Replacement of communal components.

The Boiler Upgrade Scheme includes qualifying ground source installations using shared ground loops, subject to the scheme’s detailed eligibility requirements.

Is a Ground Source Heat Pump Suitable for My Home?

A GSHP may be worth considering where:

The property has accessible outside space.
A borehole can be accommodated.
The existing boiler needs replacing.
The home uses oil, LPG or direct electric heating.
The property is being extensively renovated.
Underfloor heating is being installed.
Radiators can be upgraded.
A plant room or cylinder cupboard is available.
The homeowner is considering long-term heating investment.
Several properties could share the ground collector.

Suitability depends on more than the garden.

The assessment should consider:

Room-by-room heat loss.
Insulation.
Air leakage.
Radiator and pipe sizes.
Hot-water demand.
Electrical capacity.
Available plant space.
Local geology.
Land access.
Planning and environmental requirements.
Installation budget.
Expected length of ownership.

A site with ample land may still be unsuitable if access is impossible or the ground contains extensive services. Conversely, a property with a small garden may accommodate a borehole where geology and access permit.

Heat-Loss Calculations

The heat pump should be selected from a room-by-room heat-loss calculation.

This calculation considers:

External wall areas.
Roofs and floors.
Windows and doors.
Construction and insulation values.
Ventilation and air leakage.
Desired room temperatures.
Local winter design temperatures.
Heat transfer to unheated spaces.

The result determines:

Required heat-pump output.
Ground-collector capacity.
Radiator or underfloor-heating output.
Required flow temperatures.
Pipe sizes.
Heating-zone requirements.
Electrical demand.

A heat pump should not be sized solely from the output of the existing boiler. Older boilers are frequently larger than the building’s calculated space-heating requirement.

Radiators and Underfloor Heating

Heat pumps generally work most efficiently when supplying larger heating emitters at relatively low water temperatures.

Wet underfloor heating is well suited to this approach because it uses a large floor area to release heat.

Existing radiators may also be retained where they can provide sufficient output at the proposed flow temperature. Others may need to be:

Enlarged.
Replaced with double- or triple-panel radiators.
Supplemented.
Converted to fan-assisted emitters.
Rebalanced.
Served by altered pipework.

The installer should provide room-by-room emitter calculations showing that each room can maintain its design temperature.

Simply connecting a heat pump to radiators designed around a high-temperature boiler may result in slow warm-up, poor comfort or inefficient operation.

Heating Pipework

A GSHP system may circulate a greater volume of water than the boiler system it replaces.

The designer should check:

Main heating flow and return pipes.
Branch pipe sizes.
Radiator connections.
Underfloor-heating manifolds.
Pumps.
Zone valves.
Hydraulic separation.
Buffer vessels where required.
System resistance.
Required flow rates.

Small-bore or restricted pipework can limit performance even where the radiators themselves are large enough.

A proper survey should identify whether pipework can be retained or whether sections require upgrading.

Domestic Hot Water

Ground source heat pumps normally provide domestic hot water through a storage cylinder.

The cylinder should be compatible with heat-pump operation and sized for:

The number of occupants.
Number of bathrooms.
Bath sizes.
Shower flow rates.
Simultaneous use.
Reheat times.
Available cupboard or plant-room space.

A conventional cylinder designed for a boiler may have an undersized heating coil and may not be suitable for reuse.

The design must also provide an appropriate method of periodically raising stored-water temperature where necessary for hygiene control.

Space Required Inside the Property

The heat-pump unit may resemble a tall appliance or plant cabinet. Some systems integrate the domestic hot-water cylinder, while others use a separate cylinder.

Additional equipment may include:

Ground-loop manifolds.
Pumps.
Expansion vessels.
Buffer vessels.
Heating controls.
Electrical isolators.
Water-treatment equipment.

Energy Saving Trust notes that an internal ground source unit containing a cylinder can occupy roughly the space of a large American-style refrigerator. Actual dimensions vary considerably between products and system arrangements.

The plant layout should provide enough clearance for commissioning, maintenance and eventual component replacement.

Ground Source Heat Pump Cost

The ground source heat pump cost depends heavily on the collector system and work required within the property.

Energy Saving Trust currently gives a typical cost of approximately £29,000 for a domestic ground source heat pump using trenches. A borehole installation can cost considerably more; its broader heat-pump guide gives an indicative figure of up to approximately £57,000 where borehole drilling is required. These are national estimates rather than fixed quotations.

The final cost may be affected by:

Property heat demand.
Heat-pump capacity.
Horizontal trenches or boreholes.
Ground conditions.
Access for machinery.
Number and depth of boreholes.
Specialist surveys.
Length of pipework.
Plant-room location.
Hot-water cylinder.
Radiator upgrades.
Underfloor heating.
Heating-pipe alterations.
Electrical work.
Three-phase supply requirements.
Controls and monitoring.
Landscaping and reinstatement.
Planning or environmental applications.
Professional design and project coordination.

A quotation showing only the heat-pump unit does not represent the complete GSHP system cost.

Geothermal Heat Pump Cost

The geothermal heat pump cost searched by homeowners will usually include the same elements as a ground source installation.

The most significant difference between quotations is often the ground collector.

A project using shallow horizontal trenches may cost substantially less than one requiring:

Multiple deep boreholes.
Difficult drilling conditions.
Restricted-access drilling equipment.
Specialist environmental assessment.
Long underground pipe routes.
Extensive internal alterations.
Major radiator and pipework upgrades.

Quotations should separate the following elements:

Heat-pump equipment.
Ground collector.
Borehole or excavation work.
Internal heating alterations.
Electrical work.
Hot-water storage.
Controls.
Commissioning.
Reinstatement.
VAT.
Provisional or excluded work.

This makes it easier to compare proposals on a like-for-like basis.

Boiler Upgrade Scheme Grant

As of 17 July 2026, the Boiler Upgrade Scheme provides £7,500 towards an eligible ground source heat-pump installation in England and Wales.

From 21 July 2026 until 31 March 2027, eligible off-gas-grid properties replacing oil or LPG heating can receive an increased grant of £9,000. The grant is applied as an upfront reduction to the installer’s quotation rather than being paid to the homeowner after installation.

The installer must be MCS certified and makes the application on the property owner’s behalf. Ofgem allows six months for an approved ground source installation to be completed, reflecting the additional work involved compared with many air source projects.

Heat-pump installations also benefit from 0% VAT on qualifying energy-saving installations until 31 March 2027 under the current scheme arrangements.

Grant eligibility should be confirmed before contracts, drilling or excavation work begins.

Ground Source Heat-Pump Running Costs

A heat pump uses electricity but can deliver more heat energy than the electrical energy it consumes.

Energy Saving Trust uses a broad illustration of around three units of heat for each unit of electricity used. Actual seasonal performance depends on the complete installation and how it is operated.

Running costs will be influenced by:

The property’s annual heat demand.
Heat-pump efficiency.
Ground-loop design.
Required flow temperature.
Radiator sizing.
Hot-water consumption.
Heating controls.
Electricity tariff.
Indoor temperature settings.
System maintenance.

A poorly designed GSHP operating at unnecessarily high temperatures may use considerably more electricity than a correctly sized system serving suitable radiators or underfloor heating.

How Should a GSHP Be Controlled?

Heat pumps normally perform best when maintaining relatively steady temperatures rather than repeatedly heating a cold property at very high output.

Controls may include:

Weather compensation.
Heating curves.
Room-temperature sensors.
Separate heating zones.
Underfloor-heating controls.
Hot-water scheduling.
Smart tariff integration.
Energy monitoring.
Remote diagnostics.

The controls should adjust the heating-water temperature to the lowest level capable of keeping the home comfortable.

Homeowners may need to use a GSHP differently from a gas or oil boiler. Longer heating periods at lower water temperatures can provide better efficiency and steadier comfort.

Electrical Supply

The electrical supply should be assessed before the final heat-pump model is selected.

The electrician and heating designer should consider:

Heat-pump starting and running current.
Immersion-heater demand.
Electric backup heaters.
Existing consumer-unit capacity.
Main fuse rating.
Electric vehicle charging.
Solar panels and batteries.
Electric cooking.
Other significant household loads.
Single- or three-phase requirements.

The project may require:

A dedicated electrical circuit.
New cabling.
Consumer-unit alterations.
Local isolation.
Network-operator notification or approval.
An upgraded incoming supply.

These costs should be identified during the design stage.

Planning Permission

A domestic ground source or water source heat pump in England is normally considered permitted development and may not require a planning application.

However, homeowners should check with the local planning authority where:

The property is listed.
It is within a conservation area.
Excavation affects protected trees.
Engineering works are extensive.
Buildings or external plant are proposed.
Local planning restrictions apply.

Planning Portal also advises that ground source installations undertaken after 1 October 2023 may require an Environment Agency permit or confirmation that an exemption applies.

Rules differ across England, Wales, Scotland and Northern Ireland, so the requirements applicable to the particular property should be checked before work begins.

Building Regulations

Building Regulations can apply to:

The heating-system design.
Energy efficiency.
Hot-water storage.
Electrical work.
Structural alterations.
Penetrations through walls and floors.
Fire stopping.
Drainage.
Excavations close to buildings.

Where an unvented cylinder is installed, its safety valves, discharge pipework and commissioning require particular attention.

The homeowner should retain:

MCS certification.
Electrical certificates.
Building Regulations documentation.
Heat-loss calculations.
System-design information.
Ground-loop and borehole records.
Pressure-test results.
Commissioning documents.
Warranty information.
Control instructions.

Choosing a GSHP Installer

For an installation using the Boiler Upgrade Scheme, the heat pump must be installed and commissioned by an MCS-certified installer.

A capable project team may include:

An MCS heat-pump designer and installer.
A ground-loop designer.
A borehole drilling contractor.
A geologist or hydrogeologist.
An electrician.
A heating engineer.
A Building Regulations specialist.
A planning or environmental consultant.
A landscaping contractor.

Homeowners should request evidence of experience with the proposed type of ground collector, not only general heat-pump experience.

What Should a GSHP Quotation Include?

A detailed quotation should identify:

Heat-pump manufacturer and model.
Design output.
Room-by-room heat-loss calculations.
Proposed flow temperatures.
Estimated seasonal performance.
Horizontal loop or borehole design.
Total collector length.
Number and depth of boreholes.
Ground-loop fluid.
Manifold arrangement.
Hot-water-cylinder type and capacity.
Radiator or underfloor-heating alterations.
Heating-pipe upgrades.
Electrical requirements.
Controls and zoning.
Excavation or drilling.
Spoil removal.
Ground reinstatement.
Planning and environmental responsibilities.
Testing and commissioning.
MCS certification.
Boiler Upgrade Scheme contribution.
Manufacturer and workmanship warranties.
VAT.
Exclusions and provisional sums.

Ground conditions are not always fully known before excavation or drilling. The quotation should explain how unexpected rock, water, access difficulties or additional drilling will be valued.

Ground Source or Air Source Heat Pump?

A ground source heat pump usually has a higher installation cost than an air source heat pump because of the trenching or drilling work.

A GSHP may offer:

No outdoor fan unit.
Stable ground-source temperatures.
Quiet external operation.
Long-lived buried collectors.
Good potential for shared systems.
Suitability for larger rural properties.

An air source heat pump may offer:

Lower installation cost.
Faster installation.
Less ground disturbance.
No trenches or boreholes.
Easier installation on smaller sites.

Energy Saving Trust currently uses typical installation estimates of approximately £11,000 for an air source heat pump and £29,000 for a trench-based ground source system.

The correct choice depends on the site, budget, heat demand and long-term plans for the property.

Find a Ground Source Heat-Pump Installer Through APN Boilers

APN Boilers brings together experienced heating professionals serving homeowners throughout the UK.

A successful GSHP installation should combine:

An accurate heat-loss calculation.
A correctly sized heat pump.
A ground collector matched to the property.
Suitable radiators or underfloor heating.
Adequate heating pipework.
Correctly sized hot-water storage.
Effective low-temperature controls.
Suitable electrical capacity.
Professional commissioning.
MCS and Building Regulations certification.

Whether you are considering horizontal trenches, vertical boreholes or a shared ground loop, the property and ground conditions must be assessed before the system is specified.

Tell APN Boilers about your property, existing heating system, available land and hot-water requirements. We will help you find an appropriate professional to advise on the design and installation of your ground source heat pump.

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