Hot-water energy centre: the blue buffer tank on its legs, circulation pumps, plate heat exchangers and bare pipework on a concrete plinth

Skid, front left — Inzonex Modular Insulation, hot-water skid

Explained

Heat networks, and what changed in 2026

One boiler house. Two hundred flats. Nobody in those flats has a boiler.

Most buildings make their own heat. A heat network does it the other way round. One energy centre generates the heat and pushes it out as hot water. Buried insulated pipes carry it to every building or dwelling on the network. Each home gets a small unit on the wall instead of a boiler. It is ordinary engineering, and until 2026 in Great Britain it was almost entirely unregulated. This is what changed and what it means.

What it is

Start from the building

The normal arrangement

A block of flats where every flat has its own boiler. That is a hundred boilers, a hundred flues and a hundred service visits. It is also a hundred things to replace in fifteen years.

The heat network arrangement

One energy centre generates all of it. Insulated pipes carry the hot water to the buildings. Inside each dwelling a heat interface unit turns it into the flat’s heating and its hot taps. No combustion in the flat, no flue, no gas safety check.

The words people use

District heating and heat network mean the same thing. Communal heating usually means one energy centre serving one building rather than several. An energy centre is a plant room; a substation is where the network hands heat over to one building.

Why anyone builds one

One large heat source is easier to run efficiently, easier to change later, and easier to decarbonise than a hundred small ones. Swap the source in the energy centre and every connected dwelling changes with it, without anyone entering a single flat.

The catch

Why it needed regulating

You cannot switch

A household on gas or electricity can change supplier. A household on a heat network is connected to one pipe from one operator, usually for the life of the building. There is no market pressure on the price at all.

And the losses are on the bill

Heat leaks out of the distribution pipework continuously, all year, whether or not anyone has the heating on. That heat was generated and it is paid for by the people connected. A badly performing network shows up as a bill, not as a fault anyone can see.

The complaints route came first

Advice and advocacy services for heat network consumers started in April 2025, before any duty landed on operators. The route to complain opened before there was anything to complain against.

What changed

Ofgem, from 27 January 2026

There is a regulator now

Under the Heat Networks (Market Framework) (Great Britain) Regulations 2025, Ofgem regulates heat networks in England, Scotland and Wales. The authorisation conditions took effect on 27 January 2026. Operating a relevant heat network is now something you are authorised to do, with obligations attached, rather than something you simply do. Northern Ireland is a separate jurisdiction.

Operators have to register

Details of the network’s organisation, ownership, financial resilience and consumer protection arrangements must be given to Ofgem by 26 January 2027. The digital service for doing it opened in private beta on 28 April 2026.

Consumers got standards

Guidance published on 13 January 2026 covers Standards of Conduct, quality of service, and billing and transparency. It also covers back-billing, heat supply contracts, protections for vulnerable consumers and security of supply. It is mainly for domestic consumers, with some provisions reaching non-domestic ones.

And performance has to be reported

Data reporting guidance followed on 10 March 2026, and enforcement guidelines with a penalty policy on 20 February 2026. How the network actually performs stops being a private number.

The technical side

HNTAS, run by DESNZ

A separate scheme

The Heat Network Technical Assurance Scheme sets what a network has to meet technically and has it assessed rather than asserted. It is run by DESNZ, not by Ofgem, and the two sit alongside each other.

What has been published

86 draft Code documents. Of those, 58 are technical specifications and assessment procedures for new-build networks and 26 are for networks already in the ground. The rest are the Heat Network Technical Standard TS1 and the Metering and Monitoring Standard. The consultation ran from 21 January to 15 April 2026.

It reaches existing plant

A quarter of those documents are written for networks already running. So the scheme reaches an operator with an energy centre built ten years ago, not only the next scheme.

The launch year is not settled

Published sources differ - some say 2026, others 2027 - and it is described as phased either way. Take the date from DESNZ if a decision depends on it.

Zoning

Where networks become the default

England, led by DESNZ

Zoning designates areas where a heat network is the expected answer rather than one option among several. Strategic and local authorities in England were invited to submit zone opportunity areas by 29 May 2026 to inform the pipeline of future zones.

What it changes

Inside a zone the question stops being whether to connect. That moves the work for anyone who builds, operates or maintains network plant. It moves it a geography at a time rather than a customer at a time.

For the plant room

The part this site is about

Reported performance is measured performance

Data reporting, technical assessment and billing transparency all push the same way: an operator has to be able to show how the network performs. Distribution losses and return temperatures become numbers somebody reads.

Most of the loss is unreachable. Some of it is not.

Nobody digs up a street to improve insulation. In the energy centre the loss is visible, measurable and fixable in a day. On most networks it is also the part nobody ever insulated, because it was never anybody’s reported number.

And it runs continuously

A network energy centre is worked on while it runs. Insulation that has to be cut to reach a valve, a meter or a strainer does not survive the first intervention. That is a poor position for an asset now under technical assessment.

Checked on 6 September 2026

Every date above comes from Ofgem and DESNZ publications read on that day. This is a live programme and the dates move. Confirm anything you are going to act on against the source rather than against this page.

Reference

What happened, and when

Date	What happened	What it means
April 2025	Consumer advice and advocacy begins	The complaints route opens before the duties
13 January 2026	Consumer protection and pricing guidance	Conduct, billing, vulnerable consumers
23 January 2026	Registration guidance	What operators will have to submit
27 January 2026	Authorisation conditions take effect	Ofgem begins regulating heat networks in Great Britain
20 February 2026	Enforcement guidelines and penalty policy	The framework gets consequences
10 March 2026	Data reporting guidance	Performance becomes reportable
28 April 2026	Registration service opens, private beta	The mechanism for registering
26 January 2027	Registration deadline	Organisation, ownership, financial resilience, consumer protection

Date · What happened · What it means. From Ofgem and DESNZ publications, checked 6 September 2026 — confirm against the source before acting.

Asked about heat networks, and what changed in 2026

Questions.

Answers distinguish modelled heat-loss estimates from equipment selection and service guidance.

What is a heat network?

Heat generated in one place and piped as hot water to many buildings or dwellings, instead of each having its own boiler. One energy centre, buried insulated distribution pipework, and a small heat interface unit in each home in place of a boiler. District heating means the same thing.

What is the difference between a heat network and communal heating?

Scale. Communal heating usually means one energy centre serving one building - a block of flats. A heat network, or district heating, serves several buildings through distribution pipework between them. The engineering is the same; the losses and the regulation are not.

Who regulates heat networks in the UK?

Ofgem, for Great Britain - England, Scotland and Wales - under the Heat Networks (Market Framework) (Great Britain) Regulations 2025. The authorisation conditions took effect on 27 January 2026. Northern Ireland is a separate jurisdiction not covered by these regulations.

When did heat network regulation start?

The authorisation conditions came into effect on 27 January 2026, which is when Ofgem began regulating heat networks in Great Britain. Consumer advice and advocacy services had already started in April 2025.

Do heat network operators have to register with Ofgem?

Yes. Details of the network’s organisation, ownership, financial resilience and consumer protection arrangements are due by 26 January 2027. The registration digital service opened in private beta on 28 April 2026.

What is HNTAS?

The Heat Network Technical Assurance Scheme, the technical standards side, run by DESNZ rather than Ofgem. DESNZ has published 86 draft Code documents. They include 58 technical specifications for new-build networks and 26 for existing ones. The rest are the Heat Network Technical Standard TS1 and the Metering and Monitoring Standard. It is phased, and published sources differ on whether the launch is 2026 or 2027.

What is heat network zoning?

Designating areas in England where a heat network is the expected solution, led by DESNZ. Strategic and local authorities were invited to submit zone opportunity areas by 29 May 2026 to inform the pipeline of future zones.

Why can’t heat network customers switch supplier?

Because they are connected to one pipe from one operator, usually for the life of the building. There is no competing supply to move to, which is the reason consumer protection had to come from regulation rather than from a market.

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