Community Heat Pumps
Heating a whole street or housing development does not necessarily mean every home needs its own borehole or completely independent heat-pump installation.
A community heat-pump system can share some of the most expensive infrastructure between many homes. This can be particularly attractive for housing estates, apartment developments and groups of neighbouring properties where communal land is available.
What is a community heat pump?
There are two main ways of sharing heat-pump infrastructure.
Central community heat pump
A central system uses one or more large heat pumps to produce heat for multiple properties.
The heat is distributed to individual homes through insulated underground pipes, much like a small-scale district heating system.
Shared heat source → Central heat pump → Heat network → Individual homes
This removes the need for a separate heat pump at every property, although the communal system and heat-distribution network need to be maintained.
Shared ground-loop heat pumps
An alternative is a shared ground loop.
Instead of giving every house its own expensive borehole, a number of boreholes can be installed in communal land and connected together.
The underground loop then supplies several properties.
Shared boreholes → Shared ground loop → Individual heat pump in each home
Each property has its own relatively small ground-source heat pump, while the expensive underground heat source is shared.
This can provide many of the benefits of ground-source heating without every homeowner having to find space for and pay for an individual borehole.
Why share the boreholes?
A normal ground-source heat-pump installation can be expensive because specialist drilling equipment is required to create a borehole that may be around 100–200 metres deep.
A housing development could instead install a carefully designed borehole field underneath suitable communal land.
The cost of bringing drilling equipment to the site, carrying out surveys and installing the underground infrastructure can then be shared between many properties.
Once completed, very little of the system may be visible above ground.
Could communal green spaces be used?
Potentially.
Modern housing developments often contain communal areas such as landscaped spaces, verges and other land maintained by an estate management company.
Subject to ownership, existing utilities, geology, access, planning requirements and the necessary permissions, some of this land could potentially accommodate boreholes for a shared ground-loop system.
The surface can normally be reinstated after drilling, leaving the boreholes underground.
This means a communal grassed area could potentially continue to look and function much as it did before.
What would be installed in each house?
With a shared ground-loop system, each participating property would normally still have its own ground-source heat pump.
However, the homeowner would not require their own dedicated borehole.
Two pipes from the communal ground loop would connect the property to the shared underground system.
The heat pump would then extract low-temperature heat from this loop and raise it to a useful temperature for heating the house.
One of the goals of future high-temperature heat-pump technology is to make these installations increasingly compatible with existing heating systems, reducing the need for extensive changes to radiators and pipework.
What about hot water?
The heat pump can also provide domestic hot water.
Traditional installations commonly use a hot-water cylinder, although increasingly compact cylinders and thermal-storage technologies may reduce the amount of space required in the future.
A community system therefore does not necessarily mean that hot water has to be distributed all the way from a central plant.
With a shared ground loop, each house can produce its own heating and hot water.
What happens if one heat pump breaks down?
This is an important advantage of a shared ground loop compared with one central heat pump.
If every house has its own heat pump, failure of one unit only affects that property.
The communal underground infrastructure continues operating for everyone else.
Homeowners can also retain individual control over their heating rather than relying on a central heating plant to determine when heat is available.
Could homes join at different times?
Potentially, yes.
A shared ground-loop network could be designed with capacity for additional properties to connect later.
For example, an estate might initially have 20 participating homes. Other homeowners could potentially connect in the future, provided sufficient capacity was included in the design and the installation met the applicable technical and funding requirements.
This could make a project considerably easier than requiring every homeowner on an estate to agree to participate at the same time.
Could the Boiler Upgrade Scheme help?
In England and Wales, eligible ground-source heat pumps connected to a shared ground loop can qualify for the Boiler Upgrade Scheme (BUS).
Importantly, support is associated with eligible individual properties rather than simply providing one grant for the entire shared loop.
At the current standard £7,500 grant level, this could theoretically represent:
- 10 eligible homes — up to £75,000 of BUS support
- 20 eligible homes — up to £150,000
- 50 eligible homes — up to £375,000
- 100 eligible homes — up to £750,000
Eligibility and grant rules must always be checked before committing to a project, and an eligible installer would normally handle the BUS application process.
This potentially makes shared ground-source heating particularly interesting because public funding from multiple eligible installations can contribute towards a much larger overall project.
Example: a 40-home estate
Imagine a development containing 40 houses and a large communal landscaped area.
Instead of drilling a separate borehole in every garden, a specialist could investigate installing a borehole field underneath the communal area.
The system might look like this:
Communal land
↓
Shared borehole field
↓
Underground shared ground loop
↓
Connections running around the estate
↓
Individual ground-source heat pump in each participating home
The exact number and depth of boreholes would be calculated by engineers based on the heating requirements of the participating homes and the local geology.
If 20 properties initially participated, their eligible heat-pump installations could potentially receive individual BUS support while the shared infrastructure was designed to allow additional homes to connect later.
Could an estate management company organise it?
A managed freehold estate may be particularly well suited to investigating this idea because an organisation already exists to manage communal infrastructure and land.
The exact powers of a management company depend on its legal structure, ownership of the land and the property deeds.
A possible project could involve the management company granting permission for communal land to be used for the boreholes and distribution network, while individual homeowners choose whether to connect.
Alternatively, a specialist energy or heat-network company could potentially own and maintain the shared infrastructure.
Legal advice would be required before establishing such an arrangement.
Would everyone have to pay for maintenance?
Not necessarily.
The financial structure could be designed in several ways.
Participating homeowners might jointly own the system, the management company might own it, or a specialist company could finance and operate the shared ground loop and charge connected households.
It would therefore be important to establish who owns the infrastructure, who maintains it, what happens if somebody sells their house and whether households that do not participate are expected to contribute.
These issues should be agreed before installation.
Why isn’t this done everywhere?
Shared ground-loop systems have considerable potential, but there are practical obstacles.
Existing estates were generally not designed with heat networks in mind. Underground electricity, water, drainage, telecommunications and other services have to be considered.
Drilling rigs need suitable access, and local geology determines how practical and productive boreholes will be.
There are also legal questions surrounding communal land, ownership and long-term maintenance.
Perhaps most importantly, somebody has to coordinate all of the participating homeowners, installers, landowners and funding.
For a new housing development, many of these problems can be addressed before the houses are built.
Could this be the future of residential heating?
Potentially.
Instead of thinking of every borehole as belonging to one house, ground heat could eventually be treated more like a utility.
A street might have access to:
Electricity
Water
Telecommunications
Shared ground heat
A homeowner wanting ground-source heating would then connect to the existing ground loop rather than commissioning an entirely new borehole.
The expensive underground infrastructure could serve homes for many decades, while individual heat pumps could be replaced or upgraded as technology improves.
This could make ground-source heating much easier to install, less visually intrusive and potentially considerably cheaper than treating every property as a completely separate project.
Could it work where you live?
If you live on an estate with communal land, a shared ground-loop system may be worth investigating.
A preliminary feasibility study would normally consider:
- How many homes could participate
- Annual and peak heating requirements
- Available communal land
- Ownership of that land
- Access for drilling equipment
- Existing underground utilities
- Local geology
- Possible borehole locations and depths
- Distance between homes and the ground loop
- Existing heating systems in participating homes
- Current grant eligibility
- Estimated installation cost per household
- Ownership and maintenance of the completed network
The first step does not need to be committing to an installation.
A residents’ management company or group of homeowners could initially investigate whether the estate is technically and financially suitable for a shared ground-source heat-pump network.
Grant amounts, eligibility criteria and heat-network regulations can change. Always check the current Boiler Upgrade Scheme rules and obtain professional technical and legal advice before committing to a communal heating project.