“Do I really need to change how I manage my heat network?”
Many housing providers and property managers are asking this question. Across the UK, the heat network sector is changing quickly. With the Heat Network Technical Assurance Scheme (HNTAS) coming into effect in 2027, compliance is no longer optional. Instead, it plays a key role in keeping your operations running smoothly, controlling long-term costs, and building resident trust.
Although this may feel like a lot to take on, taking the right steps now can simplify the process later.
What is HNTAS and when does it start?
HNTAS will set minimum technical standards that all heat networks in the UK will need to meet. The Department for Energy Security and Net Zero (DESNZ) is introducing the scheme to improve efficiency, reduce carbon emissions, and delivery more reliable and affordable heating & hot water, or cooling, to residents.
The scheme is still being finalised, with a planned launch in 2027.
How will heat networks be assessed?
HNTAS will introduce a national assessment and certification framework for every heat network. As par tof this framework, assessors will review networks across six core elements:
- Energy centre: The main plant room where heat is generated for the heat network.
- District distribution network: The pipework that connects multiple buildings or phases across a wider site or area.
- Substation: Points that step heat down for different blocks or phases (e.g. via plate heat exchangers).
- Communal distribution network: The pipework that moves heat around individual buildings.
- Consumer connection: Where heat enters homes via heat interface units (HIUs).
- Consumer heat system: The heating and/or cooling, and hot water systems on the consumer side of a consumer connection.
How will the HNTAS assessment work?
Assessors will review each element across eight lifecycle stages for new-build networks. Meanwhile, existing networks will follow a separate five-milestone process.
New networks
For new-build heat networks, DESNZ’s draft technical specifications require checks at key points from concept design through to ongoing operation.
| Assurance phase | Stage |
| Feasibility | Stage 1: Concept design |
| Design | Stage 2: Developed design (optional) Stage 3: Technical design |
| Construction | Stage 4: Construction design Stage 5: Installation Stage 6: Commissioning |
| Operation (initial) | Stage 7: Operation and maintenance (initial 2 years) |
| Operation (ongoing) | Stage 8: Ongoing monitoring |
If a network meets the standards at each stage, it will receive a Statement of Conformity. Gateways at the end of each phase validate designs up to Stage 5 and then verify delivery and performance from Stage 5 onwards.
Existing networks
Ofgem has granted existing networks ‘deemed authorisation’, which allows operators to continue operating legally while they work towards registration and full compliance.
Instead of design‑stage checks, operators must demonstrate efficiency using metering data and performance calculations. In addition, networks built before 2014 can follow a longer, more flexible pathway, with additional time to meet the standards.
| Milestone | Post-2014 | Pre-2014 |
| 1: Register heat network | Year 1 | Year 1 |
| 2A: Demonstrate meeting minimum metering and monitoring requirements | Year 3 | Year 3 |
| 2B: Demonstrate meeting threshold performance, with a Milestone 2 Statement of Conformity | Year 3 | Year 3 |
| 3A: Submit Heat network performance improvement plan to reach certification | Year 3 | Year 4 |
| 3B: Demonstrate metering and monitoring requirements at dwelling level for all end-user connections | – | Year 5 |
| 4: Certification 1 – Meeting performance requirements | Year 6 | Year 8 |
| 5: Certification 2 – Meeting operation and maintenance requirements | Year 8+ | Year 10+ |
What do we need to do to achieve HNTAS compliance?
While HNTAS remains under consultation, you can already take several practical steps to prepare as a housing provider or property manager.
Step 1: Get to know your heat network inside out
Start by getting a clear picture of your heat network: where your meters are, whether they’re connected to communication hubs, and how often they capture and send data. This means checking installations, carrying out site surveys, and reviewing past consumption and performance data.
Step 2: Mind the gap
Once you know what you’ve got, look for what’s missing. This could be:
- Absent or outdated metering points
- Monitoring points that don’t align with what HNTAS is likely to require, or
- Meters that aren’t communicating reliably or frequently enough.
Where something isn’t working, consider whether equipment can be recommissioned or whether a retrofit is the sensible option.
Step 3: Make sure your data works for you
HNTAS will lean heavily on network performance and measurable outcomes. So, rather than simply collecting data, start using it to understand where improvements can be made.
Look at:
- Overall efficiency trends
- Where heat is being wasted (i.e. by looking at your Volume Weighted Average Return Temperature (VWART))
- How well your energy centre is operating (e.g. by monitoring bypass volumes)
Ongoing monitoring and clear performance reporting make it easier to spot emerging issues early. This proactive insight will help you make informed decisions about maintenance or upgrades, helping to make your network more efficient, exactly what HNTAS sets out to do.
What is the regulatory timetable for HNTAS?
Understanding the timeline helps you plan your actions. Here are the main dates to keep in mind:
- 21st January 2026: HNTAS consultation launched
- 27th January 2026: Ofgem commence role as regulator of heat networks. All existing heat networks are deemed temporarily authorised, and must comply with authorisation conditions.
- 15th April 2026: HNTAs consultation deadline, with full response expected in early 2027.
- Summer 2026: Publication of guidance documents
- 2027: Regulatory commencement of HNTAS
Beyond registration, operators will need to meet minimum metering and monitoring requirements and achieve certification milestones likely from early 2027. Aligning your operations with these milestones now makes compliance part of your everyday routine rather than a last-minute challenge.
HNTAS may seem complex, but breaking the process into steps makes it manageable. First, understand your network and ensure meters are accurate. Then fill in the gaps. Once you have the data reporting systems in place, it’ll then be easier to monitor your network, identify issues early, and report to Ofgem.
For support on how to best implement these steps for your heat network, our Solutions team would be happy to help.
