If your heat network project is being designed to CIBSE CP1, you might assume you're already well positioned for HNTAS and TS1. That assumption is partly right but partly where projects are getting caught out.
The Heat Network Technical Assurance Scheme (HNTAS) and Technical Standard 1 (TS1) build on the CP1 principles most good engineers are already working to. But they change something more fundamental than the technical requirements: they change who is accountable for demonstrating compliance, when that demonstration has to happen, and what evidence you need to produce. That's where preparation matters.
The UK government's heat network regulation programme has been advancing through consultation and development for several years. The direction of travel is clear, and the projects being designed now will be the first to feel the difference. Understanding what HNTAS and TS1 require and reviewing whether your current processes are set up to meet them, is a practical step you can take now, before the scheme is fully implemented.
HNTAS is the proposed quality assurance framework for heat networks in Great Britain, developed as part of the Heat Network Regulation programme led by DESNZ and overseen by Ofgem. Its purpose is straightforward: to raise design and installation quality across the sector, improve consumer protection, and establish a consistent technical baseline for new schemes.
If your project falls within scope and applicability will depend on the final regulatory framework, including network type, scale, and ownership structure, you would be expected to:
Applicability isn't straightforward, and you shouldn't assume it does or doesn't apply to your scheme without reviewing the latest guidance from DESNZ and Ofgem. Getting that assessment wrong in either direction carries risk.
TS1 isn't starting from scratch. It builds directly on CIBSE CP1. The Heat Networks: Code of Practice for the UK, first published in 2015, which has long been the industry benchmark for design, installation, commissioning, and operation.
If you've been designing consistently to CP1, much of what TS1 requires will be familiar. The standard draws on the same principles: pipework specification, hydraulic design, substation and HIU selection, commissioning rigour. What changes is the accountability structure around those principles.
Under TS1, these aren't just best practice benchmarks. They become a defined regulatory baseline that you are expected to demonstrate compliance with, at specific points in the project, in a specific form. That shift from guidance to regulation is what makes early preparation important, even for teams who are already doing good heat network engineering.
TS1 sets the technical baseline for heat network design and installation under HNTAS. Its requirements span:
One important note: the precise quantitative requirements within TS1, specific figures for heat loss limits, pressure parameters, and similar, should be verified directly against the current published standard before you cite them in project specifications or commercial documents.
For contractors, the change control implications are significant. Variations to heat network components (an HIU model substitution, a pipework specification change, an energy centre layout revision) need to be assessed for TS1 alignment before you approve them. A change that moves the network away from its documented design basis may affect your ability to meet the scheme's requirements at handover.
EDC has been engaged with the heat network regulation programme throughout its development. Rather than waiting for full implementation, we've been adapting our processes progressively so that the projects we're delivering today are already aligned with where the framework is heading.
In practice, that means six specific things:
Specification development. Our standard heat network specifications have been updated to reflect TS1's requirements across pipework, insulation, HIU and substation design, commissioning, and documentation. Every project we start now is being designed to the incoming standard from day one.
Design review process. We've embedded a structured TS1 review at key RIBA stages into our heat network projects, creating a documented audit trail of design decisions rather than a last-minute compliance check.
Commissioning requirements. Our commissioning specification defines the scope of witnessed testing, the format of commissioning records, and the minimum content of the technical handover package -- so the evidence HNTAS requires is generated as part of normal process, not assembled retrospectively.
Documentation management. We've developed a document management framework that structures the technical record in line with HNTAS evidence requirements, capturing design intent, installation records, and commissioning outputs in a form that supports compliance demonstration.
Quality assurance alignment. Our internal QA process includes a specific HNTAS and TS1 checkpoint at detailed design, practical completion, and handover, applied consistently across all heat network projects.
Regulatory monitoring. We track published updates from DESNZ and Ofgem and update our internal guidance when the regulatory position evolves. We've also been reviewing live client schemes against TS1's emerging requirements, in a number of cases surfacing specification or design gaps that are far easier to address during design than at commissioning.
With the regulatory programme actively progressing, the time to prepare is during design, not after the scheme goes live. Here's where to focus, by role:
If you're a developer or project client:
If you're an architect or design team lead:
If you're a main contractor:
The projects that navigate HNTAS and TS1 most effectively will be those where compliance has been built into the design and delivery process from the outset, through specification, design review, commissioning management, and documentation, not treated as a checkpoint at the end.
EDC works with developers, contractors, and design teams across the full heat network lifecycle, from feasibility and strategic design through to commissioning and handover. Our approach is practical and project-specific: we help you understand what the regulatory programme means for your scheme, identify where your current processes need updating, and put in place the technical framework to demonstrate compliance as your network is designed and built.
If your project hasn't yet been reviewed in the context of HNTAS and TS1, contact EDC to discuss where you stand.
Paul Whyte
With 20 years industry experience, Paul is a highly accomplished MEP professional with a background spanning mechanical engineering, building services design and energy infrastructure. His career has taken him from mechanical design consultancy through to senior client-side roles.
Prior to joining EDC, Paul spent six years in client-side leadership, managing MEP strategy and energy infrastructure across large residential portfolios. This experience gives him an instinctive understanding of the pressures developers and asset managers face, and allows him to deliver engineering solutions that are as commercially grounded as they are technically sound.
With 20 years industry experience, Paul is a highly accomplished MEP professional with a background spanning mechanical engineering, building services design and energy infrastructure. His career has taken him from mechanical design consultancy through to senior client-side roles, before joining EDC as Associate Director, a journey that gives him a genuinely end-to-end perspective on how buildings are designed, delivered and operated.
With a BEng Tech and a BSc degree from Dublin Institute of Technology, Paul combines deep technical knowledge with the commercial awareness that comes from years of operating at senior level.
Most recently, Paul spent six years in client-side leadership, managing MEP strategy and energy infrastructure across large residential portfolios. This experience gives him an instinctive understanding of the pressures developers and asset managers face, and allows him to deliver engineering solutions that are as commercially grounded as they are technically sound.
