You've received a connection notice: the 6-month clock

A letter about connecting your building to a heat network can be unsettling, especially if it mentions deadlines and penalties. This guide explains what a formal heat network connection notice will mean once zoning is in force, how the six-month clock works, and how to use that time well.

First, a reality check. If you have a letter in your hand today, it is not a statutory notice.

No statutory notice can be sent yet

Connection notices are part of heat network zoning, and zoning isn't switched on yet:

Until both of those change, nobody can serve a notice that legally requires you to connect. You might still get a letter from a district heating developer or a council, especially in one of the early zone areas. That's a commercial or informal approach. It may be worth engaging with, and early conversations can give you more say later, but you're under no legal obligation to respond within any set time.

If a letter claims you must connect under zoning law, ask which zone it relates to, when it was designated and under which regulations. You'll quickly find out whether it's genuine.

Everything below describes the process the government has proposed. It could change when the regulations are drafted.

Who sends a notice, and when

Zoning has two local players. The zone coordination body runs the zone locally, and in practice this will usually be your council or combined authority. Coordination bodies will be set up by local government; the zoning authority can step in if councils cannot agree within 28 days[source]. The zone developer builds and operates the network. Zone developers will be appointed through competition, with exclusive rights to develop a heat network in the zone delivery area[source].

The developer decides which buildings it wants to connect and when, then asks the coordination body to serve notices. The zone coordination body issues the notice within 2 weeks of the zone developer's request[source].

That means a notice is unlikely to come out of the blue. In most cases the developer will have done its own survey of the area, and may well have approached you informally first. If your building is in an area where zoning work is under way, check our zone checker and watch for those early conversations.

What you'd expect a notice to contain

The regulations will set out exactly what a notice must say, and they haven't been published. But a notice that is going to start a legal clock should, at the very least, make clear:

• which building or buildings it covers, and the legal basis for requiring connection
• the date it was issued, so you know when the six months started
• the proposed connection window
• who to contact at the zone developer and at the coordination body
• how to apply for an exemption

If any of that is missing or unclear when the time comes, ask for it in writing straight away. Don't let ambiguity eat into your six months.

The agreement phase

Once you've received the notice, the main clock starts:

In practice, that means two possible outcomes by the end of month six. Either you've agreed a connection date with the zone developer, or you've applied for a temporary exemption. Doing nothing isn't one of the options.

Agreeing a connection date isn't the same as agreeing every commercial term on the spot, but it's the point where you commit. So the six months are really for understanding the deal: the technical design, what works are needed in your building, the charges, and who pays for what. Our guide to connection costs explains the charges you're likely to see.

The connection window

The physical connection happens within a separate period:

The overlap matters. Your connection window could start while you're still negotiating, so the time available to plan building works may be shorter than you'd assume if you added the two periods together. Ask the developer early when it expects the window to open and close, and whether there's flexibility to line it up with your own plans, such as a planned boiler replacement, a refurbishment or a quiet period in your building's year.

The temporary exemption route

If you have good reasons not to connect within the window, you can apply for a temporary exemption during the agreement phase. Temporary exemptions can last up to 2 years from the end of the proposed connection window[source].

The proposed grounds include existing low-carbon heating with life left in it, legal barriers, building safety remediation works, physical or technical barriers and conservation constraints. The legal ground can matter to landlords: it covers legal or contractual requirements that prevent connection, such as restrictive covenants or lease terms[source]. Each ground has its own conditions. Our exemptions and deferrals guide goes through each ground and the evidence you'd need.

A heat network zoning exemption application takes time to prepare well. If you think you might need one, start gathering evidence in the first month, not the fifth.

Penalties

The government proposes penalties for buildings that don't comply:

The figures are designed to matter even to large organisations. They aren't law yet, and the detail of when and how they would be applied will come with the regulations. The practical lesson is simple: a notice is not something to file and forget.

A month-by-month plan

Six months goes quickly, especially in a large organisation where decisions need sign-off. Here's a plan that leaves room for slippage. Our notice countdown tool works out the actual dates from the day your notice arrives.

Month 1: get organised. Confirm the notice is genuine and note the date. Appoint one person to own the response. Tell the people listed in the next section. Pull together your heat demand figures (see our 100 MWh guide), plant records and any lease or covenant terms that touch heating. Send the developer your first list of questions.

Month 2: understand the offer. Meet the developer. Get the technical design, proposed charges and connection window in writing. Commission a site survey if the developer hasn't. If you think you may have exemption grounds, start building the evidence now.

Month 3: test the numbers. Compare connection with your alternatives, such as replacing boilers or installing your own heat pump. Our heat network vs heat pump guide can help. Take legal advice on the draft connection agreement, leases and any covenants.

Month 4: decide. Choose between agreeing a connection date and applying for a temporary exemption. Deciding now leaves two months for negotiation, approvals and paperwork.

Month 5: negotiate and approve. Settle the connection date and any terms still open. Get internal sign-off from whoever holds the budget. If you're applying for an exemption, finalise and submit the application.

Month 6: close it out. Sign the agreement or confirm your exemption application has been received. Don't leave this to the last week. File everything.

Who to tell internally

A connection affects more people than the facilities team. Early on, brief:

• Finance, because connection charges and heat tariffs will change your budgets for years.
• Estates and capital projects, because plant replacement and refurbishment plans may need to change.
• Legal or company secretary, because of the notice itself, lease terms and the connection agreement.
• Tenants or occupiers, where they pay for heat or would be affected by works. Our guide for landlords and leaseholders covers this in more detail.
• Senior leadership or the board, given the size of the proposed penalties.

What to ask the zone developer

Put your questions in writing and keep the answers. Useful ones include:

1. What exactly will be installed in our building, where, and who owns it?
2. What are the connection charge, the standing charge and the unit rate, and how will they change over time?
3. What heat sources will supply the network now, and later?
4. What flow and return temperatures will the network run at, and will our heating system need changes to work with them?
5. When will the connection window open and close, and is there flexibility?
6. What disruption should we expect during works, and for how long?
7. What happens if the network has an outage?
8. What service standards apply after connection, and how do we complain?

If the developer can't answer something within the agreement phase, record that you asked. On that last question, it helps to know that heat networks are now regulated. Ofgem became the regulator on 27 January 2026[source], and the Energy Ombudsman accepts heat network disputes, usually after 8 weeks with the supplier[source].

Records to keep

Keep a single file with the notice and envelope or email showing the date received, every letter and email with the developer and coordination body, meeting notes, your heat demand calculations, survey reports, legal advice, internal approvals and any exemption application with its evidence. If there's ever a dispute about whether you engaged properly, this file is your answer.

If the process feels like too much to handle alongside your day job, independent heat network consultants who specialise in connection negotiation or zoning compliance can help you through it. Where a lease, covenant or contract is involved, take legal advice too.