Heat Network Registration: What to Do Before Ofgem's 26 January 2027 Deadline

Many building owners, housing associations, managing agents and estates teams do not think of their building as a "heat network". They think of it as a block with a boiler room. Under the new rules, that difference no longer matters: if heat from one central source serves more than one home or premises, the building is very likely a regulated heat network, and someone is responsible for registering it.

This guide explains what counts as a heat network, what the 2027 deadline means, and the practical engineering steps to take now so registration, and the technical standards that follow it, do not become a last-minute scramble. For the full service, see our heat network compliance page.

The key dates

27 January 2026: Ofgem became the heat networks regulator for Great Britain under the Energy Act 2023. From this date, operators and suppliers of relevant heat networks must follow Ofgem's authorisation conditions.

Until 26 January 2027: networks that were already operating are treated as deemed authorised, so they can keep running while the regime beds in. This is a transition period, not an exemption.

26 January 2027: the deadline for existing operators and suppliers to register with Ofgem, under authorisation condition A4. New networks after this point need authorisation before they operate.

From 2027: the Heat Network Technical Assurance Scheme (HNTAS) is expected to begin certifying networks against technical standards for design, construction and operation.

Is your building a heat network?

The Energy Act 2023 defines two types. A communal heat network is a single building divided into separate premises, such as flats, student rooms or commercial units, that share heat from one central source. A district heat network serves two or more buildings from a shared source.

In practice, the buildings most often caught are blocks of flats served by one plant room, purpose-built student accommodation, sheltered and retirement housing, mixed-use developments with a shared boiler house, and campuses or estates where one energy centre heats several buildings. If you are unsure, the simplest test is: does one set of boilers, heat pumps or a CHP unit supply heat or hot water to more than one separately occupied space?

Operator or supplier: who has to register?

The regime separates the operator, who runs and maintains the network, from the supplier, who supplies heat to the end customers. On many sites the same organisation is both, often a housing association, landlord or managing agent. On others the roles are split, for example where an energy services company runs the plant and a landlord bills residents.

Agreeing who holds each role is the first job, because each role carries its own conditions. If the plant room is maintained under a contract, the contractor is usually not the operator in the regulatory sense, but the records they keep are what the operator will rely on.

Five engineering steps to take before the deadline

Registration is an administrative step, but the information behind it, and everything Ofgem and HNTAS will expect afterwards, comes from the plant room. These are the steps we recommend starting now.

1. Survey and map the network. Record what the heat source is, which buildings and premises it serves, and how heat reaches them: primary pipework, plate heat exchangers, heat interface units (HIUs) and risers. Many older communal systems have no up-to-date drawings at all.

2. Build an asset register. Tag and record every boiler, pump, heat exchanger, pressurisation unit, HIU and meter with make, model, serial number, age and condition. An accurate register is the foundation for registration, maintenance planning and future replacement budgets.

3. Check the metering. Confirm which premises are metered, whether the meters are working and readable, and whether the readings are actually used for billing. Faulty or missing heat meters are one of the most common problems on communal systems, and fair, accurate billing is central to the new consumer protections.

4. Get the maintenance records in order. Service histories, gas safety records, water treatment logs and fault records should be complete, dated and easy to find. Gaps are much easier to close now than when a regulator or assessor asks for evidence.

5. Baseline performance. Measure how the network actually performs: flow and return temperatures, heat losses and running hours. HNTAS builds on CIBSE CP1 (2020), which is about networks running efficiently in practice, not just on paper. Live monitoring, such as HeatFlow.ai, turns this from a one-off survey into ongoing evidence.

What happens if you miss it?

Ofgem has enforcement powers over heat network operators and suppliers, including financial penalties, and operating a relevant heat network outside the authorisation regime after the deadline exposes the responsible organisation to enforcement action. Just as importantly, residents on communal systems now have stronger consumer protections, so poor reliability, unclear billing and slow repairs carry regulatory as well as reputational risk.

Leaving preparation until the final months of 2026 is the biggest risk. Surveys, asset registers and metering repairs all take time, and the closer the deadline gets, the more networks will be competing for the same engineers.

How Adapt Gas helps

Adapt Gas is a Gas Safe registered commercial heating and gas engineering contractor based in Manchester. We do the physical work behind heat network compliance: plant room surveys, asset tagging and registers, metering checks, planned maintenance, repairs and upgrades, with digital records for every visit. We work with housing associations, landlords, managing agents, student accommodation operators and estates teams across the North West, with nationwide cover for multi-site portfolios.

Read more on our heat network compliance service, or call 0161 526 5588 to arrange a plant room survey ahead of the 2027 deadline.