Heat networks 2026: HNTAS and Ofgem

What has changed for 2026

From 27 January 2026 Ofgem begins regulating heat networks across Great Britain, with registration, data reporting and consumer‑protection duties phasing in during 2026 and fuller enforcement by 2027. Treat 2026 as the compliance start line.

The Government has also published the Heat Network Technical Assurance Scheme (HNTAS). HNTAS turns best practice into mandatory, auditable technical requirements for new and existing communal and district systems, drawing on CIBSE CP1 and phasing in to keep the burden proportionate.

Finally, notifications and compliance data will be moved to Ofgem’s digital service in spring 2026, replacing the old OPSS notification route under the Heat Network Metering & Billing Regulations. Meter installation and accuracy duties continue in the interim.

What HNTAS means for commercial buildings

HNTAS will require evidence that your network is engineered and operated to a clear baseline. Focus on four essentials.

• Temperatures and hydraulics. Lower primary flow temperatures, stable ΔT, balanced circuits and responsive substation controls to cut losses and improve comfort.
• Insulation and distribution. Verified insulation standards on mains, risers and laterals to reduce distribution losses and avoid unintended internal heat gains.
• Metering and billing integrity. Calibrated meters, robust data paths and billing that stands up to scrutiny, including where non‑domestic and microbusiness customers are supplied.
• Commissioning and monitoring. Evidence‑based commissioning with measurable acceptance tests, then routine monitoring and corrective actions supported by assurance routes.

Ofgem authorisation — the essentials for 2026

Ofgem is introducing authorisation conditions for all GB heat networks. Late‑2025 consultations covered registration, nominated operator accountability, regular data reporting, fair‑pricing and consumer standards, and enforcement. Final guidance now moves into implementation in 2026, with the majority of conditions enforced by 2027. Mixed‑use and multi‑occupancy sites will feel this most, because pricing transparency and service standards apply across customer groups.

Your 90‑day action plan

1. Create a network register and gap assessment. List every communal or district system, operator details, customer classes, temperature regimes, distribution losses, metering architecture and known defects. Map gaps against Ofgem’s registration and data requirements and HNTAS technical themes.
2. Stand up the data pipeline. Prepare to submit outages, complaint metrics, meter reliability, consumption and billing integrity through Ofgem’s digital service as it launches in spring. Retain current HNMBR metering duties until HNTAS supersedes technical elements.
3. Deliver quick technical wins. Lower flow temperatures where feasible, retune substation controls and upgrade insulation on risers and laterals. These reduce losses immediately and improve tenant experience.
4. Refresh tariffs and communications. Put in place a tariff review process, document cost allocation and indexation, and publish plain‑English explanations to reduce disputes as fair‑pricing guidance lands.
5. Update contracts and SLAs. Add obligations for data provision, outage response, meter accuracy, performance testing and audit rights so you can evidence compliance to Ofgem and occupiers.

Scotland — what to watch

The Scottish Government has published a draft Buildings (Heating and Energy Performance) and Heat Networks (Scotland) Bill and signalled an early 2026 consultation on installation and maintenance licences for heat networks, with legislation to follow after the May 2026 election. Engage through LHEES and prepare for licensing conditions and potential zonal connection duties.