The heat network revolution

The UK’s legally binding commitment to achieving net zero emissions by 2050 is driving a transformation across the built environment, fundamentally shifting the way we heat our homes, offices, and cities, writes Joseph Lazell of Cundall.

Heat is responsible for approximately 40% of the UK’s energy consumption and more than 20% of our greenhouse gas emissions. However, this national transition is not just an environmental necessity; it is a critical social challenge. Reliance on volatile fossil fuel prices has led to a rapid escalation in fuel poverty across the country, while cold, inefficient housing continues to pose a significant public health risk.

Addressing the heating of our buildings is one of the most significant challenges for the UK’s net zero ambition, making finding a low-carbon and affordable way to heat our buildings an absolute imperative.

The role of heat networks

District heating already exists as a key low-carbon infrastructure solution across Europe, where it supplies over 60% of citizens in countries like Denmark. These systems distribute heat, often from centralised, low-carbon sources, such as large-scale heat pumps, recovered waste heat from industrial processes, or geothermal energy, through insulated pipe networks to multiple buildings.

However, UK heat networks have long held a negative market perception due to high, opaque costs and poor service quality, which has hindered wider adoption.

The UK government is now aiming to turn the tide, committing to a renewed strategic focus on heat networks as a vital, scalable solution for decarbonisation. While these systems currently supply only around 3% of the nation’s heat demand, the government has set an ambitious target of reaching 20% by 2050 through this renewed drive.

This transformation is underpinned by two new fundamental regulatory changes: the Heat Network Technical Assurance Scheme and Heat Network Zoning. These mandates are designed to finally address historical consumer detriment, provide investment certainty, and accelerate deployment.

Crucially, from 27th January 2026, Ofgem will also begin regulating heat networks, treating them in the same way as established utilities like gas, water, and electricity. By early 2027, Ofgem aims to have published the full set of rules for operators and suppliers, including pricing and Guaranteed Standards of Performance.

The Heat Network Technical Assurance Scheme

HNTAS is the new mandatory quality and consumer assurance framework for heat networks. Due for official launch by Ofgem in 2026, it aims to tackle historical issues of high costs and poor service by requiring all heat networks to meet robust technical and performance standards.

All district heat networks and communal heating systems, such as those within residential blocks, will fall under HNTAS. These heat networks will be legally required to be certified at key stages (design, construction, operation) to prove compliance. Failure to factor in this mandatory gateway process risks expensive delays or regulatory failure.

The breadth of the HNTAS mandate is crucial for design teams and developers to understand. Its scope applies not only to large, city-wide district systems but also to the smallest communal networks serving heat to two or more dwellings. This means that compliance is required even for systems typically viewed as ‘local,’ such as a standalone apartment block with rooftop air source heat pumps serving just a few homes.

Accelerating deployment with heat network zoning

Heat network zoning, the second core mandate, is the government’s primary strategic planning tool, designed to complement HNTAS. Since district heating requires a certain density of heat demand to be economically viable, zoning is intended to accelerate rollout and guarantee demand.

Working with 28 local authority partners, the Department for Energy Security and Net Zero has identified potential heat network zones across the country. Published zoning maps are available on the GOV.UK website for areas such as Greater Manchester, Liverpool, Leeds, and Sheffield. With these maps established, the initial construction rollout is targeted to begin in 2026.

The core policy impact is a connection mandate. Within these zones, many new-build and existing buildings with significant heat demand will be legally required to connect. Even where immediate connection isn’t feasible, new developments near a zone must be designed as ‘heat network ready’ as a minimum. This critically means design teams must ensure internal heating systems can operate efficiently at the low temperatures a modern, low-carbon heat network typically provides, allowing for cost-effective future connection.

Navigating the regulatory shift

The combined pressure of HNTAS (stringent performance) and zoning (mandatory connections) represents a significant market intervention requiring a shift in design and operational thinking for developers and design teams. Moving forward, it will be crucial to consider if future projects are located within heat zoning areas to inform financial feasibility from day one and secure long-term asset value with an appropriate servicing strategy.

Cundall is currently implementing future-proofed heating strategies for a diverse range of sectors. We have a breadth of experience in engineering low-temperature, high-performance heating systems to exceed best practice standards, ensuring compliance with draft HNTAS guidance and building in flexibility for future district network connections. Our range of experience within London’s existing priority heat zone has also provided us with practical expertise in de-risking the planning process where connections are mandated.

For larger masterplan sites that justify their own low-carbon energy centres, our power teams are also advising clients on the associated grid demands and liaising with network operators to secure and design the necessary electrical infrastructure.

Getting ahead of legislation

Heat networks are set to play a key role in heat delivery for the UK. This strategic expansion, underpinned by the new quality standards of HNTAS and the demand certainty of zoning, is a necessary step if the UK is to meet its net zero obligations and, if regulated effectively by Ofgem, holds the opportunity to significantly reduce fuel poverty.

For developers and design teams it is  vital to get ahead of the legislation now, ensuring any impact to proposed projects is integrated into the design process to secure regulatory approval and ensure long-term asset value.

• Joseph Lazell is partner at Cundall