The Department for Energy Security and Net Zero (DESNZ) has published the draft Heat Network Technical Assurance Scheme (HNTAS) Technical Specifications and Assessment Procedures for New Build Heat Networks.
This latest release represents a significant milestone in the development of the HNTAS framework and follows the publication of TS1 last month, as well as the HNTAS Overview Technical Specifications and Assessment Procedures released earlier this year.
What’s been published
HNTAS is a performance-based assurance scheme, which contains impartial assessment and independent certification, to ensure that heat network performance outcomes are achieved and maintained.
To facilitate this, Technical Specifications and Assessment Procedures set out the requirements which need to be fulfilled as part of HNTAS, and the assessment activities undertaken to provide assurance that these are met.
What is a Technical Specification
A Technical Specification sets out the requirements which need to be met at a given Phase of a heat network’s development, for each Element within a heat network.
These requirements consist of:
- The Technical Requirements to be met
- The Performance Monitoring Requirements to be met
- The Key Failures to be avoided at each stage
- The Evidence Requirements to be provided
What is in an Assessment Procedures document
The Assessment Procedures set out the assessment activities to be undertaken to provide assurance that the standards within a Technical Specification have been met.
For each requirement set out in a Technical Specification, the document sets out:
- The minimum level of assessment
- The activities which form the Assessment Procedure for that specific requirement
Their roles within the scheme
Within HNTAS, a heat network is separated into constituent Elements:
- Energy Centre
- District Distribution Network
- Substation
- Communal Distribution Network
- Consumer Connection
- Consumer Heat System
The development of a New Build heat network is split into the following Phases:
- Feasibility
- Design
- Construction
- Operation
The 46 documents of draft Technical Specifications and Assessment Procedures, alongside the draft version of TS1 released in November and draft Overview documents released earlier this year, form part of the Code documentation structure within HNTAS.
Why this matters
For a sector that has long called for greater clarity and consistency, this release marks a major step forward. The documents:
- Increase clarity across design, development, delivery and operation
- Provide assurance and confidence for developers, operators, stakeholders and investors
- Support standardisation across the heat network lifecycle
- Offer greater certainty ahead of regulation
Much of the content reflects established best practice already being delivered successfully across the sector, now brought together into a clear and structured framework.
Who this is for
The HNTAS documentation gives developers, operators, contractors and consultants a comprehensive reference set for how heat networks should be designed and developed.
It provides a shared technical language and clear expectations across all stages of a new build heat network’s lifecycle.
Acknowledging industry collaboration
It is essential to highlight the scale of industry collaboration involved in developing the HNTAS framework. Over the last year this has included:
- 111 organisations and 190 individuals
- 10 stakeholder engagement groups
- 12 pilot projects supporting the development of new technical standards
This level of engagement reflects the sector’s collective commitment to raising standards and improving outcomes for customers.
For more information on HNTAS and the documents released, reach out to our Industry Standards team.
