Empowering heat networks to perform and meet net zero potential
This opinion piece first appeared on the Energy Live News website on 14 January 2026.
Empowering heat networks to perform and meet net zero potential – Energy Live News
A new regulatory technical requirement for heat networks is expected to be introduced on 27 January, but what are the benefits, and what does it involve in practical terms? The Heat Network Technical Assurance Scheme (HNTAS), expected in 2026, will ensure all heat networks meet a minimum level of consistency and performance. Synergie Environ Principal Engineer Sophie Sibley says this is a development that should be welcomed, as it will only build confidence in the quality of our heat networks.
HNTAS has been designed to build on the voluntary standard CP1 (2020) from the Chartered Institution of Building Services Engineers (CIBSE). Ofgem is the regulator for the scheme, which now shifts from the previous voluntary and guidance position to a set of mandatory requirements that must be adhered to. HNTAS covers England, Scotland and Wales and has been developed to address evidence of a number of poorly performing heat networks. It is estimated that 50,000 new residential connections will be undertaken each year, so guaranteeing that these perform correctly and well is vital.
To ensure the UK meets its 2050 net zero goals and maintains energy security, the transition to effective and reliable heat networks needs to take place. CP1 offered a good starting point and building blocks for HNTAS; however, if an individual is not mandated to undertake the best monitoring and design, there will naturally be a much lower uptake.
At its core, HNTAS is being developed to increase the transparency around heat network performance and increase accountability for the organisations involved. A poorly designed, constructed and operated heat network will offer a poor outcome and dissatisfaction for the end user.
The objectives of the upcoming HNTAS are as follows: to reduce carbon and cost; improve affordability, improve customer experience and enhance data collection and reporting.
The Energy Act 2023 defines a heat network as “a network that, by distributing a liquid or a gas, enables the transfer of thermal energy for the purpose of supplying heating, cooling or hot water to a building or persons in that building (and includes any appliance the main purpose of which is to heat or cool the liquid or gas).”
HNTAS will cover:
• communal and district heat networks
• new-build networks (HNTAS applicable from the outset)
• existing networks (HNTAS used to rectify existing issues over time).
HNTAS will be performance based, comparing design to actuality. Heat networks will be required to pass assessments to demonstrate that the network has achieved minimum technical standards. The standards will set out technical requirements that will be mandated. This is to address commonly seen issues, for example: uncontrolled flows and bypasses (which cause energy inefficiencies); poor water quality (causing corrosion and failures); high return temperatures (causing reliability issues) and unnecessarily complex heat systems.
Because of the complexity of heat networks, the assessment to comply with HNTAS is undertaken at an element level (e.g., energy centre, substation or consumer connection) rather than assessing the entire heat network in one go. Essentially, HNTAS assesses your network piece by piece.
α denotes an assessment stage. The assessment stage at Stage 2 is optional.
The network will need to pass assessments at the following stages:
1. Before the design begins
2. Before construction begins
3. Before operation begins
4. After two years of operation
These phases cover the entire heat network life cycle: feasibility, construction and operation.
What will it mean for operators?
Reassuringly, the Department for Energy Security and Net Zero emphasises that the new scheme is being designed “with deliverability and proportionality as two of its leading principles”. The department states: “Specifically, we are keen to ensure that the introduction of HNTAS does not place undue burden or cost on heat network operators or heat network consumers.”
The guidance states that the existing stock of communal and district heat networks will have “a significant transition period to get the right metering in place, to be able to prove performance”. Final performance thresholds will be set at a more tolerant level for existing networks, and existing networks will be given time to reach these.
If you are a heat network operator, are a consumer or are involved in the planning, construction, management, commissioning, operation and/or maintenance of a heat network, HNTAS will apply to you. Once you have achieved HNTAS certification, the heat network operator will be required to consistently submit data to the HNTAS digital portal to demonstrate continued compliance with the HNTAS KPIs.
Preparation and guidance
Ways to get ready:
• Email heatnetworksregulation@ofgem.gov.uk and ask to receive regular updates on the new regulations coming out.
• Utilise the Heat Training Grant to receive £500 towards the cost of heat pump training (only available to England residents).
• Work with an industry expert. Those with a CIBSE CP1 background will be a good place to start (as HNTAS builds on CP1). For any other questions, contact heatnetworks@energysecurity.gov.uk.
• Keep abreast of Building Engineering Services Association (BESA) news. BESA has been appointed as the lead training provider.
o Undertake the Introduction to Heat Network Technical Assurance Scheme course.
What does this all mean?
As with any new regulation or released guidance, there will be teething issues, and I expect nothing less for the roll-out of HNTAS.
I expect the main issue to arise from existing heat networks. When costing a new heat network to attract investors or apply for funding, the new HNTAS regulations can be factored in. However, existing heat networks won’t have done so, and the cost of retrofitting can be expensive. Does this mean that existing heat networks should be excluded from HNTAS? No. A poorly performing heat network is a cost burden to the operator and the end consumer and ultimately releases more carbon than it should. However, it does raise the question of who will pay for the retrofits to the network to meet HNTAS standards.
At the moment, the most suitable funding avenue would be via the Heat Network Efficiency Scheme (HNES). Though HNES does not cover Scotland, and while there are some funding avenues in Scotland that are similar, none are as well-suited to the optimisation of an existing heat network. An additional sticking point with HNES funding is that it covers up to 50% of eligible project capital costs for improving the network. So, again, the question is raised – who will pay for it?
A potential solution could be utilising energy performance contracts (EPC) for existing networks wanting to undertake optimisation works. An EPC is an arrangement in which a company agrees to improve the energy performance of a building or scheme and they guarantee the savings. The benefit of this is that it removes the risk, which helps attract investment.
For example, a bank may be willing to lend the capital to optimise the heat network, as the savings from the improved operation will ensure its loan is paid back. If the heat network doesn’t achieve those savings, the company that guaranteed the savings is required to pay the difference. This ensures that the company undertaking the work doesn’t promise unachievable results to win the work in the first place. Measurement and verification (M&V) is a key part of EPCs, as it checks that the guaranteed savings are actually achieved. M&V is undertaken via international guidelines (International Performance Measurement and Verification Protocol methodology), so all parties can assess, verify and ultimately trust the results.
As someone who spent part of their career undertaking M&V for various projects, I am pleased by the number of meters expected under HNTAS. Too many projects are hindered by poor metering and shortcuts taken during construction. When projects start to become more expensive due to unforeseen costs or there is a time delay, metering is often disposed of. When the heat network is being assessed, metering is an area that should be monitored with care to ensure the Metering and Monitoring Standard of HNTAS is maintained.
At present, HNTAS is expected to come into force in 2026. HNTAS is an exciting change to the industry, and all projects will be assessed using the same criteria, so success can be equally compared. Heat networks are an exciting solution to waste heat and high-carbon emissions, so HNTAS should be welcomed. As with everything, transition takes time, so I’d recommend getting a large cup of tea and a pack of biscuits and reading those Technical Specifications.
Sophie Sibley is a principal engineer at Synergie Environ. She is a qualified Energy Savings Opportunity Scheme (ESOS) Lead Assessor, Low-Carbon Consultant (Design) and previous Performance Measurement and Verification Analyst.
References
• Department for Energy Security and Net Zero (2025), ‘Heat Network Technical Assurance Scheme (HNTAS)’. Available online: https://www.gov.uk/government/publications/heat-networks-regulation-technical-standards/heat-network-technical-assurance-scheme-hntas (accessed 18 December 2025).
• CIBSE (2021), ‘CP1 Heat networks: Code of Practice for the UK (2020) (pdf)’. Available online: https://www.cibse.org/knowledge-research/knowledge-portal/cp1-heat-networks-code-of-practice-for-the-uk-2020-pdf (accessed 18 December 2025).
• Tricia Quinn, Heat Networks Consumer Protection Policy Expert (2025), ‘Heat networks regulation: consumer protection’ (presentation), UKDEA Expo 2025, 7 July 2025.
• Department for Energy Security & Net Zero (2025), ‘Heat Network Technical Assurance Scheme (HNTAS)’ (presentation), UKDEA Expo 2025, 7 July 2025.
• Department for Energy Security and Net Zero (2025), ‘Heat Training Grant: discounted heat network training’. Available online: https://www.gov.uk/guidance/apply-for-the-heat-training-grant-discounted-heat-network-training (accessed 18 December 2025).
• BESA (2024), ‘BESA appointed to lead heat network programme’. Available online: https://www.thebesa.com/besa-latest-news/desnz-appoints-besa-hntas-training (accessed 18 December 2025).
• BESA Academy, ‘Introduction to Heat Networks Technical Assurance Scheme’. Available online: https://besa.academy/local/intellicart/view.php?id=113 (accessed 18 December 2025).
• HM Government, Energy Act 2023, Part 8, Chapter 1: ‘Regulation of heat networks’. Available online: https://www.legislation.gov.uk/ukpga/2023/52/part/8/chapter/1 (accessed 18 December 2025).
• Department for Energy Security and Net
