Zoning – from pilots to statute: the real challenge for heat network zoning

As heat network zoning moves from pilot activity toward a statutory framework, the nature of the challenge is changing. The early phase of the Advanced Zoning Programme (AZP) has largely been about proving technical propositions: identifying opportunity areas, testing methodologies, refining boundaries, and building confidence that heat networks can play a significant role in decarbonising heat in dense urban areas. The next phase is different. The question is no longer whether heat networks can be delivered, but whether zoning can be implemented in a way that supports scale, pace, and market confidence.

Zone image courtesy of DESNZ.

Pilots haven’t delivered networks – and that matters

It is important to be clear about what the Tier 1 AZPs have and haven’t done. In most cases, new heat networks have not been delivered as a result of zoning. Where schemes exist, they tend to pre‑date the AZP or have progressed through political leadership, regeneration programmes, or individual project momentum rather than zoning powers. That is not a criticism of the pilots. But it does mean that zoning has not yet been tested at the point where it interacts with statutory powers, enforceable decisions, and long‑term authority accountability. As zoning moves toward statute, that interaction becomes unavoidable.

Statute changes incentives and behaviour

Once zoning becomes statutory:

• zone boundaries become consequential rather than indicative;

• exemption decisions set precedents;

• enforcement posture sends signals to developers and investors;

• and authority decisions become contestable and durable.

At this point, success depends less on technical optimisation and more on whether authority‑side governance supports delivery rather than constraining it. This is where the risk shifts.

Governance is now the delivery question

Engineering advisors remain essential. Demand density analysis, heat source identification, network routing, and system optimisation are the foundations of viable zones. Commercial advisors are equally essential. Prospectus design, competition‑for‑market structuring, financing assumptions, and delivery incentives will determine which schemes actually progress. But neither group is responsible for how zoning decisions are owned, sequenced, or interpreted over time by the market.

Developers, investors, and operators read governance signals carefully:

• Is planning genuinely embedded in zoning, or treated as a downstream constraint?

• How predictable is enforcement, and over what timeframe?

• How consistently are exemptions handled across zones?

• How stable is the authority’s posture as political and institutional contexts change?

These factors directly affect whether capital accelerates or waits.

Scaling up is harder than starting

And starting is hard enough! Much of what has worked in the AZP phase has relied on informal judgement, individual leadership, and local discretion. That flexibility has helped pilots move forward. It does not scale easily. When zoning becomes enforceable and repeatable across multiple places, informal solutions harden into expectations. Inconsistency between authorities becomes visible. Unclear sequencing creates bottlenecks. Planning and regeneration misalignment slows delivery. Without discipline, the UK risks replacing fragmented heat network development with fragmented zoning practice.

Zoning meets institutional reform

An additional complexity now entering the picture is that heat network zoning is being implemented alongside major reforms to local government. Local Government Reorganisation (LGR) and accelerated devolution are reshaping authority boundaries, planning responsibilities, asset ownership, and governance structures in many AZP areas. Some authorities are being asked to design Zone Coordination Body (ZCB) arrangements at the same time as the institutions that might ultimately host those functions are themselves evolving. ZCB responsibilities are statutory and long‑lived. Institutional reform is transitional, but disruptive. This does not argue for delaying zoning. It argues for transitional design: approaches that allow progress now without locking authorities into governance models that may not survive reorganisation or future devolution settlements.

Heat networks are becoming multi-tier infrastructure

A further development that matters for zoning design is the growing recognition that some heat network assets operate at a scale beyond local planning and control. Recent projects have seen large‑scale heat transmission infrastructure recognised as nationally significant, reflecting their role in supporting decarbonisation across multiple authorities and unlocking investment at scale. In these cases, strategic trunk assets may be consented nationally, while distribution networks, connections and local sequencing remain subject to zonal and local authority processes. This does not diminish the importance of Zone Coordination Bodies. It raises the bar. ZCBs will increasingly operate within a layered system where local zoning decisions must align with regional strategies and, in some cases, nationally significant heat infrastructure. The delivery risk here is not technical. It is governance coherence. ZCBs designed as if they sit at the top of the system risk misalignment with nationally consented assets, confusing market signals, and delays at the point where scale should accelerate.

This is not about doing less engineering – it is about doing governance better

As zoning moves toward statute, technical and commercial expertise become more, not less, important. But success now depends on whether authorities can integrate that advice within governance arrangements that are:

• clear about decision ownership;

• robust to institutional change;

• legible to the market;

• and capable of supporting delivery at pace.

Zoning will only unlock investment if the authority is seen as a reliable system steward, not just a boundary setter.

A practical test for readiness

A useful sense‑check for any area approaching statutory zoning is whether it can answer, clearly and consistently:

1. Who owns zoning decisions, and how are they assured?

2. How are planning, regeneration, and infrastructure alignment handled in practice?

3. What governs exemptions and transitions between zones?

4. How will enforcement support delivery rather than stall it?

5. How does today’s pilot‑style governance evolve into a sustainable, fundable model?

These are not regulatory design questions. They are deliverability questions.

Looking ahead

Heat network zoning remains one of the most promising tools for accelerating low‑carbon heat. But its success will depend on how governance choices made now play out as the system scales, infrastructure hierarchies emerge, markets respond, and institutions change. The challenge is no longer simply moving from pilot to statute. It is moving from insight to coherent delivery, in a way that supports investment confidence through political, organisational, and regulatory transition.