The government has launched a consultation on new mandatory technical standards for heat networks, alongside proposals for a Heat Network Technical Assurance Scheme (HNTAS).
The consultation is now live and closes on 15 April 2026.
These proposals stem from the Energy Act 2023, which gave government the powers to regulate heat network technical standards across Great Britain. Until now, much of the sector has relied on voluntary guidance. The intention now is to formalise those expectations and introduce a clear system for demonstrating compliance.
What is HNTAS?
HNTAS is the proposed assurance framework that will sit behind the new regulations. In simple terms, it will require heat networks to meet minimum technical standards and to prove that they are doing so.
Networks will need to pass assessment points at key stages in their lifecycle, from design through to operation. Certification will be required before a network can operate, and operators will then need to submit performance data on an ongoing basis to show standards are being maintained.
The scheme is expected to launch in 2027, with a phased introduction to allow time for the sector to prepare.
It will apply to networks of all sizes, from communal systems in residential buildings to large district heat networks, and will cover both new and existing schemes.
From voluntary guidance to regulation
Much of the technical foundation for HNTAS builds on CIBSE CP1 (2020), the established Code of Practice for heat networks in the UK. Prior to CP1, heat networks were largely guided by the Heat Networks (Metering and Billing) Regulations 2014 and associated voluntary guidance, which focused mainly on metering, billing, and consumer protections rather than technical performance.
HNTAS now formalises technical expectations across the lifecycle of a heat network, from design and construction through to operation, turning much of what was previously guidance into mandatory standards.
A new draft standard, TS1 – the Heat Network Technical Standard – has been developed to replace CP1 as the principal reference point. It is largely based on CP1 but introduces additional requirements in some areas.
Draft Technical Specifications and Assessment Procedures have also been published as part of the consultation, setting out what networks must achieve, and how compliance will be assessed.
How will this impact existing networks?
Existing heat networks will not be expected to meet the same thresholds overnight. The proposals include transition periods and staged milestones, recognising the practical challenges of upgrading legacy systems.
More permissive initial performance thresholds are proposed, alongside time to implement appropriate metering and monitoring. The overall direction, however, is clear: existing networks will need to demonstrate performance and move towards certification.
What does HNTAS mean for heat suppliers?
If your organisation supplies and charges for the supply of heating, cooling or hot water to customers through a heat network or communal heating, then it is defined as the “heat supplier” under HNTAS.
Your organisation will need to:
- Ensure that networks meet technical standards, and maintain evidence for assessments.
- Monitor heat network performance on an ongoing basis
- Upgrade systems, introduce new metering, or adjust network designs to meet minimum standards.
The importance of heat networks
Heat networks are expected to play a significant role in decarbonising the UK, but performance across the sector has been inconsistent. The government’s stated ambition for the HNTAS is to improve efficiency, reduce carbon emissions, strengthen reliability and increase confidence among consumers and investors.
If implemented as proposed, HNTAS will reshape how heat networks are designed, constructed and operated. For developers, operators, local authorities and housing providers, this consultation is an opportunity to influence how proportionate and workable the final framework will be.
How to respond to the consultation
The consultation on the Heat Network Technical Standards is open until 15 April 2026. Stakeholders are encouraged to review the draft documents and submit views before the deadline.
With regulation expected from 2027, the decisions taken now are likely to define the technical and compliance landscape for heat networks for years to come.
HNTAS support for heat network suppliers
If you control or operate a heat network, Sustainable Energy First can support you in navigating HNTAS compliance, from assessing current network performance, through to preparing the evidence needed for assessments. For advice, get in touch.
