Guidance

HNTAS: Existing heat networks - draft overview of assessment procedures

An overview of the draft procedures that Heat Network Technical Assurance Scheme (HNTAS) registered assessors will need to follow to assess a heat network’s compliance with HNTAS technical requirements.

• From: Department for Energy Security and Net Zero
• Published: 21 January 2026

Applies to England, Scotland and Wales

Documents

DRAFT: HNTAS existing heat networks - overview of assessment procedures

Ref: HNTAS-EX-AP-XX-M0

PDF, 482 KB, 23 pages

Details

This draft overview of the series of assessment procedures is applicable to all elements within an existing heat network. It details the activities to be undertaken to verify compliance with the various Milestone requirements in the upcoming Heat Network Technical Assurance Scheme (HNTAS).  

The documents are for use by:

• heat network assessors
• heat network operators

This assessment procedure overview for existing heat networks has a corresponding HNTAS: Existing heat networks - draft overview of technical specifications.

Next steps

We will be requesting feedback on the information in these documents. We will run a change management process in parallel with the HNTAS technical standards consultation which closes on 15 April 2026.

We will make final versions of these documents available before the scheme starts.

Published 21 January 2026