Shared ground loop systems

Shared ground arrays, individual heat pumps, ownership and regulation.

A shared ground loop connects a common closed ground or water heat exchanger to individual heat pumps serving more than one property. The shared infrastructure provides low-temperature source fluid. Each property’s heat pump raises that temperature for its own space heating and hot water.

This is different from a conventional district-heating network, where a central energy centre distributes water already hot enough to use in the buildings. It is also different from one large communal heat pump supplying several flats through heat interface units. These arrangements may all be called heat networks, but their energy use, metering and failure points are not the same.

What is shared and what remains individual

The shared side can include boreholes, horizontal ground arrays, submerged closed loops, headers, distribution pipework, circulation pumps, controls and source-side backup or heat rejection. A dwelling normally has its own water-to-water heat pump, heating controls and hot-water arrangement.

The resident therefore buys electricity for the dwelling’s heat pump in many designs and can choose an electricity supplier in the usual way. There may also be a separate access, standing or service charge for use and maintenance of the common loop. Other ownership models meter and sell thermal energy differently. The contract and physical diagram need to establish which model applies.

An individual heat-pump fault may affect only one home, but failures of common pumps, controls, headers or the ground array can affect several. The design needs clear responsibility and contingency for both levels.

The loop needs a network design

Sharing infrastructure does not remove the ground-array calculation. The designer must consider the combined annual energy extraction, simultaneous and diversified peak loads, source temperatures, pressure loss, pump energy and interaction between boreholes or trenches.

Important inputs include:

the heat loss and hot-water demand assigned to each property
how many heat pumps can run together and at what source flow
future connection capacity and whether unconnected plots are included
heat added back by cooling or other sources
the minimum and maximum loop temperatures allowed by every connected heat pump
pump control at low and high demand
metering, alarms and evidence that one property is not degrading service to others

The loop may operate close to ground or ambient temperature, which can reduce distribution heat loss compared with a hot-water network. It still needs insulation or condensation control appropriate to its temperatures, and the circulation electricity must be included in system performance.

Ownership is part of the engineering

Ground arrays and distribution mains are long-life assets that cross property boundaries. Legal rights are needed for installation, access, repair, replacement and future connection. The scheme should identify who owns each section, who is the operator, how costs are recovered and what happens if that organisation fails or transfers the asset.

Residents need to know:

what they own inside the home
who services the individual heat pump
who maintains the loop and common pumps
how access or standing charges can change
what performance or availability the network promises
who handles leaks, low source temperatures and outages
whether a replacement heat pump must come from an approved list
what rights apply on sale, lease, disconnection or redevelopment

A low first-year charge is not enough information for an asset intended to serve several properties over a long period.

Heat-network regulation

As at 22 July 2026, Ofgem classifies shared ground loops using closed ground or water loops with individual consumer heat pumps as heat networks within Great Britain’s heat-network regulatory regime. Ofgem says they have fewer regulatory obligations than some other heat networks, but they are not outside the framework. Its registration guidance recognises utility, non-utility and small private ownership models.

The current consumer-protection framework covers matters including standards of conduct, service quality, billing transparency, back-billing, contracts, vulnerable consumers and security of supply. Which duties apply can depend on the operator, supplier and charging arrangement, so the scheme should identify the authorised parties rather than simply state that it is “Ofgem regulated”.

Northern Ireland is outside this Great Britain regime. Environmental permissions for the ground or water array also remain separate from consumer regulation.

Grants are not the ownership model

As at 22 July 2026, the Boiler Upgrade Scheme includes ground source heat pumps on shared ground loops in England and Wales. Eligibility and capacity conditions should be checked on the live scheme pages for each project. The presence of support does not settle who owns the shared infrastructure, how the resident is charged or whether a particular future replacement will qualify.

Grant amounts and scheme limits are deliberately not repeated here because they can change without altering how the technology works.

Cooling and other heat sources

Some shared loops accept heat from buildings that need cooling or from another low-temperature source. That can improve annual ground balance, but it requires hydraulic and control design. Heat rejected at one time or place is not automatically available when another building needs it.

Cooling can also create condensation risks and change electricity use, planning, metering and resident contracts. It should be described as a designed service, not assumed from the words “ambient loop” or “fifth generation”.

Connection and property records

A useful information pack should include:

the network schematic and boundary between shared and private equipment
ground-array design assumptions and remaining connection capacity
source temperatures, pump energy and monitoring arrangements
ownership, easements and operator and supplier identities
tariff structure, indexation and worked bill examples
maintenance, outage and emergency responsibilities
heat-pump replacement and compatibility rules
regulatory registration and complaints route
as-built records for buried infrastructure

A shared loop allows one source infrastructure system to serve multiple individual heat pumps. Each connected property then depends on the communal asset, its operator and the contract governing access and costs.

Applies to

Heat

Last reviewed

22 Jul 2026