Heat Network Regulations Are Changing. Is Your Building Ready for HNTAS?
If you own, manage, or operate a building or estate served by a heat network — whether a communal system within a prestigious multi-tenanted office building, a portfolio of commercial properties across the UK, or a city-scale district heat network — one of the most significant regulatory changes in a generation is heading your way.
The Heat Network Technical Assurance Scheme (HNTAS), underpinned by the Energy Act 2023, will introduce mandatory minimum technical standards for heat networks across Great Britain. With the scheme on track for a phased launch from 2026–2027, the window to prepare is now — and those who act early will be significantly better positioned than those who wait.
At Zerith, our CIBSE-accredited Heat Network Consultants are already working with commercial real estate portfolios, individual landmark buildings, and district energy network operators to understand their compliance obligations and plan the most cost-effective path to compliance. Here's what you need to know — and how we can help.
What Is HNTAS and Why Does It Matter?
HNTAS is the UK government's new mandatory technical compliance framework for heat networks, developed by the Department for Energy Security and Net Zero (DESNZ). It replaces the sector's previous reliance on voluntary best practices — most notably the CIBSE CP1 Code of Practice — and makes technical compliance a legal requirement for the first time.
The scheme covers the full lifecycle of heat networks, from design and construction through to long-term operation, and applies to both new build networks and existing operational systems. Its core objectives are to raise performance standards, improve reliability for end users, reduce heat losses, lower carbon emissions, and ultimately create a more trustworthy and cost-effective heat network sector.
For commercial real estate operators and district heat network managers, this is not a distant regulatory development — it is an imminent compliance obligation that requires action today.
What Does HNTAS Require?
For new build heat networks, HNTAS will introduce a three-stage Gateway assessment process, requiring networks to demonstrate compliance at pre-design, pre-construction, and operational stages, with a further assessment after two years of operation. For existing heat networks, a phased Milestone-based approach will allow operators a transition period to achieve minimum performance, metering, and monitoring standards.
Key areas covered by the technical standards include:
• Pipe insulation standards and distribution network heat loss limits
• Water flow temperatures and hydraulic balancing requirements
• Metering and monitoring obligations, including consumer-level heat metering
• Heat Interface Unit (HIU) performance and specification requirements
• Minimum performance and reliability thresholds for operational networks
• Technical Due Diligence requirements for new schemes under design
Where compliance with certain requirements cannot be demonstrated on cost-effectiveness grounds, the scheme provides a mechanism for derogations — but these must be properly evidenced and submitted. Zerith's consultants have the expertise to identify where derogations may be applicable and to build the robust technical case required to support them.
Who Does HNTAS Apply To?
Commercial Real Estate Portfolio Operators
If you manage a portfolio of office buildings across the UK — whether let to single occupiers or multiple tenants — you are very likely to have heat networks within your estate, and ESOS compliance may have already flagged them as significant energy users. HNTAS will require you to understand which of your buildings contain qualifying heat networks, assess their current technical condition against the incoming standards, and develop a clear compliance roadmap.
For portfolio operators, the challenge is scale. Assessing dozens or hundreds of buildings individually is neither practical nor cost-effective without a structured, efficient approach. Zerith offers a complete portfolio review service — starting with a rapid desktop assessment of your entire estate to identify which buildings are in scope, prioritise sites by compliance risk, and establish a clear picture of the work required before a single site visit takes place.
Prestigious Multi-Tenanted Commercial Buildings
For the operators and asset managers of landmark multi-tenanted office buildings — particularly in major city centres where communal heat networks are common — HNTAS introduces specific obligations around metering at consumer connection level, HIU performance, and the reporting of heat network performance data. Meeting these standards is not just a regulatory requirement; it is increasingly a key consideration for institutional tenants and investors who demand demonstrable ESG performance from the buildings they occupy or fund.
Zerith's technical appraisal service for individual buildings provides a comprehensive review of the existing heat network infrastructure, identifies the specific reporting points and sub-metering requirements applicable under HNTAS, and delivers a clear, costed compliance plan. Where derogations may apply — for example, where the cost of installing certain metering infrastructure is disproportionate to the benefit — we build the technical case to support this.
District Heat and Energy Network Operators
For operators of district heat and energy networks — including those serving mixed-use developments, large residential estates, and urban regeneration schemes — HNTAS represents the most comprehensive compliance challenge. The scheme applies across the full scope of the network, from the energy centre and primary distribution pipework through to consumer connections and individual HIUs.
Zerith's district network consultancy service covers the complete HNTAS compliance journey: from initial technical due diligence on systems currently in design or construction, through to operational assessments of existing networks against the incoming Milestone requirements. We also support operators in understanding and evidencing derogation cases where specific requirements present genuine cost-effectiveness challenges.
Not Sure Whether HNTAS Applies to You?
HNTAS applies to any heat network that supplies thermal energy to more than one building or property from a shared source — but eligibility is not always immediately clear, particularly for older communal systems, privately managed developments, or mixed-use estates where heat supply arrangements are complex.
To make it easy to find out where you stand, we've built a free Heat Network Compliance Checker on the Zerith website. In just a few minutes, you can carry out a straightforward self-assessment to determine whether your building or network is likely to fall within scope of HNTAS — and what your immediate next steps should be.
"Use our free Heat Network Compliance Checker at zerith.uk/energy-compliance-consultant — and get clarity on your obligations in minutes."
If you're confirmed as in scope, our team is ready to discuss the right approach for your portfolio or network and provide an initial consultation at no cost.
The Zerith Approach to HNTAS Compliance
Zerith's CIBSE-accredited Heat Network Consultants bring deep technical expertise in heat network design, operation, and performance optimisation, combined with a clear focus on delivering cost-effective compliance outcomes. We work across the full spectrum of HNTAS requirements, offering services that can be tailored to the specific needs of portfolio operators, individual building owners, and district network managers alike.
Crucially, we offer two distinct delivery pathways — giving you genuine choice over how your HNTAS compliance is managed:
Option 1 — ZECO-Enabled Self-Reporting
For organisations with capable in-house teams — whether Facilities Managers, Building Engineers, or Energy leads — Zerith's ZECO AI Platform makes it possible to self-deliver your HNTAS compliance statement, dramatically reducing or eliminating the need for ongoing external consultancy spend. The ZECO platform simplifies the complexity of HNTAS reporting: guiding your team through data collection, evidencing technical compliance against the relevant standards, flagging where derogations may apply, and generating the documentation required for submission — all within a single, intelligent platform. Zerith consultants remain on hand for technical support, quality assurance, and final sign-off, but the heavy lifting is done by your team, on your timeline, at a fraction of the traditional cost.
"The ZECO AI Platform puts professional-grade HNTAS compliance reporting in your team's hands — cutting costs without cutting corners."
Option 2 — Zerith Turnkey HNTAS Compliance
For organisations that prefer a fully managed solution, our Turnkey service places the entire compliance process in Zerith's hands. Our CIBSE-accredited consultants manage everything — from initial scoping and technical appraisal through to report preparation, derogation assessment, OPSS submission, and final sign-off — powered by the ZECO AI Platform to deliver maximum efficiency and the most competitive pricing in the market. You stay informed at every stage, with full transparency over progress and findings, but without the internal resource burden.
Whichever pathway you choose, the outcome is the same: full HNTAS compliance, delivered on time, at the lowest achievable cost.
Our broader services include:
• Portfolio Review and Scoping — rapid desktop assessment of your entire estate to identify in-scope buildings, prioritise compliance risk, and establish a clear programme of work. Flat-fee structure: £1,000 for up to 10 buildings, £2,000 for up to 20 buildings, POA for larger portfolios.
• Technical Appraisals — detailed building-level or network-level assessment to establish current compliance position, identify specific reporting points, and define the scope of works required.
• Derogation Assessment and Submission — identification of applicable derogations, development of the technical and cost-effectiveness evidence required, and submission support.
• OPSS Registration Support — building-level desktop review and submission to the Office for Product Safety and Standards as required under the Heat Networks (Metering and Billing) Regulations.
• Technical Due Diligence for New Schemes — independent review of heat network designs against HNTAS Gateway requirements, ensuring compliance is embedded from the outset and costly retrospective modifications are avoided.
• Compliance Roadmap Development — a clear, phased plan for achieving full HNTAS compliance, aligned with your capital expenditure cycles and asset management strategy.
"Zerith's CIBSE-accredited consultants deliver the most competitive and cost-effective HNTAS compliance solutions available — from a single building to a national portfolio."
Act Now — Don't Wait for the Deadline
With the HNTAS technical standards consultation closing in April 2026, final scheme documents being published ahead of the 2026–2027 launch, and training courses already live for HNTAS assessors and certifiers, the regulatory clock is ticking. Early engagement gives you the time to plan, budget, and phase compliance activity in a way that minimises disruption and cost — and positions your assets ahead of the market.
Contact the Zerith team today to book a free 30-minute compliance consultation, or use our online checker to carry out your initial self-assessment.
