Heat networks and ambient loops for build to rent landlords

What a heat network is

A heat network is one heat source serving many homes. The pipes carry hot water from a central plant to flats or houses, instead of each home having its own boiler. Ofgem puts it this way: heat networks provide heating, cooling and hot water to multiple properties in a building, or to multiple buildings, from a single source.

For a build to rent landlord, the point is that you stop being the owner of a boiler and become the owner or the customer of a heat service. That changes who is responsible when it goes wrong, and who is regulated.

What an ambient loop is

An ambient loop network, also called a fifth generation district heating network, circulates water at low temperature. A CIBSE paper on the topic describes water between 10 and 40 degrees Celsius, with heat pumps used either to take heat out of the loop or to put heat into it. That means a loop can serve heating and cooling.

The key difference from older heat networks is where the heat pumps sit. DESNZ notes that consumers on these networks often own an individual heat pump connected to the shared system. Shared ground loops are a close relative: heat is taken from the ground through a single shared array and passed to many users, each with an individual heat pump.

A single heat pump connected to a low temperature loop can achieve a high coefficient of performance, because the water is already close to the temperature it needs.

How an individual heat pump connects

In a typical arrangement there are three layers:

1. The shared loop, with its pipework, ground array or other heat source, owned and run by an operator.
2. A heat pump in each home, which takes heat from the loop and raises it to the temperature that home needs.
3. The home’s own emitters and hot water cylinder.

The planning and noise questions on the flats page are about outdoor air source units, so check with the designer what applies to a given loop. The trade-off in every case is that you depend on the operator for the loop.

Who pays what

This is where schemes differ, and you should get it in writing. The money can flow in several ways, for example:

• the developer or owner pays for the loop infrastructure
• the landlord or the tenant pays for the heat pump in each home, or the operator owns it and charges a service fee
• the tenant pays for the electricity the heat pump uses, and maybe a standing charge for the network

Which applies depends on the heat supply contract. Do not assume. Ask for a plain list of costs to the landlord and costs to the tenant, and for who owns, maintains and replaces each heat pump.

Regulation since January 2026

Ofgem began regulating heat networks in Great Britain on 27 January 2026, under the Heat Networks (Market Framework) (Great Britain) Regulations 2025. The core consumer protections cover billing, customer service, complaints handling and vulnerable customers. Heat network operators and suppliers are expected to join the Energy Ombudsman heat network scheme so that unresolved disputes have an independent route. Existing operators have to register on Ofgem’s digital service.

For a landlord, this is helpful. It means a tenant on a heat network has a regulated supplier and a complaints route, which is a floor that did not exist before.

Technical standards are separate. DESNZ states that ambient loop and shared ground loop networks are included in the Energy Act 2023 and are in scope of the Heat Network Technical Assurance Scheme, with requirements still under development in the consultation document we read. Check the current position with Ofgem and DESNZ before you rely on it.

Questions to put to an operator

Before you commit homes to a network, get written answers to these:

1. Who owns the loop, the plant and each home’s heat pump, and who is responsible for maintaining and replacing them?
2. What does the heat supply contract say about price, how the price can change and how the tenant is billed?
3. Is the operator registered with Ofgem and a member of the Energy Ombudsman scheme?
4. What happens if the operator fails or sells the network?
5. Which technical standard is the network built to, given HNTAS is still being developed?
6. How is the tenant protected if the heat supply fails in winter, and who pays for emergency heating?
7. What are the exit terms if you sell the home?

A good operator answers all seven in plain language. A vague answer is an answer.

What regulation does and does not do

Regulation sets a floor for how customers are treated. It covers billing, customer service, complaints and support for vulnerable customers, and it gives disputes somewhere to go. It does not choose the technology, decide whether a network is value for money or guarantee a price. It also does not tell you whether the network suits your portfolio. Those are commercial decisions that stay with you.

The details are in Ofgem’s authorisation conditions and its heat networks consumer protection guidance, which the operator should be able to point to. Ask for them by name.

When a heat network suits a landlord

A network is more likely to suit you when:

• you are developing or buying a large site with many homes in one place
• the design is settled before the buildings, so the loop and the plant rooms are planned in
• the operator has a track record and a clear contract
• local planning policy favours it. London Plan policy, for example, prioritises connection to district heat networks for developments in heat network priority areas, so check the local plan before you design around a loop

When it does not

A network is a poor fit when:

• you own a single house, a few flats or a small block, where individual heat pumps are simpler
• you retrofit existing homes with no shared plant space
• the operator cannot show a contract that protects you and your tenants
• you cannot find out who pays to replace the equipment when it reaches the end of its life

Most landlords reading this site own individual rented homes. For them, a heat pump in each property is the route.

How it differs from one heat pump in one property

	Single property heat pump	Ambient loop
Who owns the heat source	You	An operator or developer
Outdoor unit at each home	Yes, for air source	No
Regulator for the supply	None for the heat pump itself	Ofgem, for the network
Contract	Installer’s warranty and maintenance	Heat supply and operator contract
Fits	Existing homes	Large new sites
Funding route	Boiler Upgrade Scheme for eligible installs	Not verified, ask first

Next step

If you own individual rented homes, start with the landlord heat pump calculator and the funding overview. If you are planning a large site and want to talk to relevant independent firms, send an enquiry. There is no charge to you and no obligation.