Heat network zoning for developers and planning applicants

If you are bringing forward a new building in an English town or city, heat network zoning is one more thing to factor into your energy strategy. For developers it lands differently than it does for existing building owners. You are not retrofitting anything. You have the chance to design a building that can take heat from a district heating network from day one, for far less than it would cost to adapt it later. This guide covers what the government proposes for new buildings, how timing works, and what good practice looks like while the rules are still being written.

Where things stand

Start with the honest position. The Energy Act 2023, Part 8, Chapter 2 (sections 226 to 237)[source] gives the government powers to create heat network zones, and zoning applies to England only[source]. Those powers need detailed regulations before they do anything.

No zones have been designated yet, so no planning application today can be required to connect under zoning law.

What has happened is a lot of preparation. In October 2024 the government named the first places to develop zones: Leeds, Plymouth, Bristol, Stockport, Sheffield and two schemes in London, including Old Oak and Park Royal[source]. A second round followed in 2026: local authorities invited to submit zone opportunity areas by 29 May 2026[source]. If your site is in one of the early places, zoning is much closer for you than for most. Our zone checker shows how far work has got near any address.

Why new buildings are in scope

The government set out its policy in its response to consultation, published 21 January 2026[source]. One of the three categories of building it proposes to require to connect inside a zone is aimed squarely at developers:

The logic is simple. It is much cheaper to design a building for district heating than to convert one later. A building connected from the start never needs its own boilers or a central heat pump plant, which frees up roof and plant room space and avoids a future replacement cycle. For the zone developer, new buildings are reliable customers that help justify building the network in the first place.

If your scheme refurbishes existing buildings, the other two categories could apply as well: existing buildings with communal heating, both domestic and non-domestic[source], and existing non-domestic buildings with a wet heating system and average heat demand above 100 MWh a year[source]. Our guide to the 100 MWh heat demand threshold explains how that test is expected to work.

Timing: permission versus designation

On the government's proposal, the trigger for a new building is planning permission granted after the zone is designated. That makes timing the key question for anyone with a scheme in the pipeline.

Here's a hypothetical. Say you secure full planning permission for an office building in March, and the area is designated as a zone the following September. On the proposal as written, that building would fall outside the new-buildings category, because permission came first. A near-identical building next door permitted in October would be inside it.

Two cautions. First, the regulations are not written yet, so the exact trigger could still move. Second, real schemes are rarely that tidy. Outline permissions, reserved matters approvals, variations to an existing consent and fresh applications on a site that already has permission could each be treated differently. We have not seen published detail on how each will work, so don't build a programme around beating designation.

It's also worth knowing that falling outside the new-buildings category doesn't put a building beyond zoning for good. Once it exists, a large non-domestic building with a wet heating system could be caught by the existing-buildings category if its demand is high enough, and a residential block with communal heating could be caught by the communal category.

Designation won't arrive out of nowhere. Zone coordination bodies, usually the council or combined authority, will run the local process. Under the proposals they are set up by local government; the zoning authority can step in if councils cannot agree within 28 days[source]. We would expect some local engagement before a zone is formally designated, which should give you warning, but the designation process has not yet been set out in regulations.

Designing a building that can connect

Whatever the final rules say, if your site is near an emerging zone, designing for connection is sensible practice. None of the points below is a zoning requirement today. They are what experienced district heating engineers generally recommend.

Low-temperature secondary systems. Heat networks work best when buildings take heat at low temperatures and send water back as cool as possible. That means sizing radiators, underfloor heating, fan coils and air handling unit coils for low flow temperatures, and designing out things that push return temperatures up, such as bypasses, poorly balanced circuits and unnecessary three-port valves. A low-temperature design also suits heat pumps, so it isn't wasted if the network never reaches you. The right temperatures depend on the network and the building, and figures vary between schemes, so ask your engineer to check the design against what the likely zone developer expects.

Space and access for a substation. A connected building usually has a substation, essentially a plate heat exchanger with controls and a heat meter, where the network meets the building's own system. Leave plant room space for it, a route for the network pipes from the site boundary into the building, and access to replace equipment over the building's life. A ground floor or basement plant room close to the street often keeps pipe runs short.

Heat interface units in residential schemes. Flats on a communal or district system usually have a heat interface unit in each home. Plan cupboard space and service risers, and think about how maintenance can be done with as little disruption to residents as possible.

Metering. Build in heat meters at the building connection and, where you are supplying individual homes or tenants, at each unit. Good data supports fair billing, fault-finding and any later conversation about charges.

Interim heat. If the network won't be ready when the building is occupied, you need heat in the meantime. Ask how a temporary or interim solution can be designed so it doesn't leave expensive plant stranded once the connection is made.

Talk to the council and the likely zone developer early

Pre-application discussions are the obvious moment. Ask the planning team or the council's energy officer whether zoning work covers your site, which body is expected to act as zone coordination body, and whether a delivery partner has been chosen. Our place pages, such as Leeds and Plymouth, summarise what is public about local zoning work.

Under the proposals, zone developers are appointed through competition, with exclusive rights to develop a heat network in the zone delivery area[source]. Once one is in place for your area, it becomes the organisation you'll deal with on route, timing, technical standards and price. Useful questions include when the network is expected to reach your site, what flow and return temperatures it will run at, what it expects a substation to look like, what metering it requires, and how connection charges are worked out. Our guide to connection costs explains the main drivers.

Any connection agreement or heads of terms you sign with a zone developer will be a long-term commitment. Take legal advice before signing, particularly where it affects future tenants, leaseholders or buyers.

How exemptions might apply to new builds

The government proposes a set of heat network zoning exemption grounds. Most are framed around existing buildings, so their fit with new builds is uncertain. Three examples show why.

One ground is existing low-carbon heating with an expected lifespan of more than 2 years[source]. Whether a planned on-site heat pump system in a new building would count is something the regulations will need to answer. Another is enduring technical incompatibility that cannot be fixed without significant cost, such as direct electric heating[source]. Choosing direct electric heating for a new building in a designated zone in the hope of relying on that ground would be a risky strategy, and we wouldn't assume it will work. A third is permanent physical features, such as the structure or ground conditions, that make connection impossible[source], which could be relevant on a constrained site but is a high bar.

Where an exemption is granted on a temporary basis, it can last up to 2 years from the end of the proposed connection window[source]. Our guide to exemptions and deferrals goes through every ground.

Phased and multi-plot schemes

Large schemes built out over many years are where timing gets complicated. Imagine a hypothetical scheme of three phases. Phase one has detailed permission before designation. Phases two and three need reserved matters approval afterwards. On the proposal as it stands, phases two and three could fall within the new-buildings category while phase one does not, though how reserved matters are treated is not yet clear.

The practical answer is a site-wide energy strategy that works with or without the zone network. That might mean a central plant room designed to take a network connection later, safeguarded pipe routes and easements across the site, and early phases built to low-temperature standards so they can join when the network arrives. Get the legal side of easements and service charges checked by a solicitor.

If you plan to run your own site-wide network serving several buildings, you will probably count as a heat network operator. Ofgem has regulated heat networks since 27 January 2026[source], and a technical assurance scheme is on the way, with a planned launch in 2027, phased in[source]. Our guide to Ofgem regulation and HNTAS covers what that means.

Planning conditions and obligations

Many councils already encourage connection to district heating through their local plans, planning conditions and section 106 obligations. These often ask for a connection-ready design, or for connection once a network becomes available. We won't summarise particular policies here because they vary from council to council and change over time.

Zoning is a separate legal regime. A planning condition is not a heat network connection notice, and a zoning requirement, once in force, would come through the zoning process run by the coordination body. The two will often overlap, and councils are likely to try to keep them consistent, but read the exact wording of any condition or obligation. "Connection-ready" and "must connect within a set period of the network becoming available" are very different commitments. If you are unsure what you are signing up to, take legal advice.

It's also worth keeping the enforcement picture in mind. For buildings that are required to connect and don't, the government proposes penalties of up to £1 million or 10% of annual turnover, whichever is higher[source]. That isn't law yet, but it shows how seriously the requirement is meant to be taken.

Getting the right help

For most schemes, the key adviser is a building services engineer with district heating experience who can design the secondary system and plant room around a future connection. Heat network consultants who specialise in zoning compliance can help you read the local position and talk to the council and zone developer. You can find both in our directory under design and engineering and zoning compliance, and see who is building networks in our developer listings. Our timeline keeps track of every date as it firms up.