What architects need to know about low-carbon heat network
The Future Homes Standard (FHS) is no longer on the distant horizon. Neal Herbert, GTC Managing Director looks at how the forthcoming standard is shaping briefs, layouts and procurement decisions on sites breaking ground now.
The UK government announced that the publication of the final FHS will take place this autumn, with implementation tied to the new Home Energy Model (HEM). In practice, this points to low- or zero-carbon heat as the default for new housing, with gas being phased out.
For architects working with residential housebuilders, two networked approaches are climbing the shortlist: networked ground source heat pumps, sometimes called ambient loop “shared ground array” systems, and community heat hubs (low-temperature communal networks served by central plant). Both can unlock compliance and long-term performance if you plan for them early and design with the systems in mind.
The FHS will be assessed using the Home Energy Model rather than SAP. HEM shifts attention from headline carbon alone to the interplay of primary energy, emissions and fabric against a notional building benchmark. Draft notional specifications include a dedicated section for dwellings connected to heat networks, signalling that connection details and network temperatures will materially affect compliance outcomes. This means the model will reward efficient, low-temperature systems and penalise high losses or over-sized plant.
Ofgem has also confirmed the beginning of regulated heat networks from January 2026, offering consumer protection, technical standards and market monitoring. This stands to reduce perceived risk to developers and end-users, but also brings real obligations on metering, pricing and service levels that design teams must allow for.
Networked GSHPs drill shared vertical boreholes that feed an ambient temperature loop, and compact, in-dwelling heat pumps that then lift energy to deliver space heating and hot water. Because ground temperature is stable, a factor not currently recognised by SAP, seasonal efficiency is high and peak electrical demand is flatter than individual air-source systems, keeping the site’s electrical capacity close to, or even below, a gas-equivalent baseline.
Community heat hubs centralise low-carbon generation, using large scale heat pumps and thermal stores, which then feeds a low-temperature network into homes via Heat Interface Units (HIUs). By shifting heat production away from peak electricity prices and using thermal storage, hubs can cut peak site demand and reduce import costs.
The architectural brief: what to lock in early
- Ground and plant space
Ambient loop GSHPs need borefield real estate – often under POS, car parks or road verges – and accessible manifold zones. Plot the boreholes, separation distances and construction sequencing at masterplan stage or you will run out of “drillable” land just as value engineering bites. Community heat hubs need a proper energy centre envelope: plant room, acoustic separation, flues (if backup), and space for thermal stores and power equipment. - Utility corridors and easements
Treat the ambient loop or district mains as a fourth utility. Allocate corridors with depth, bend radii and clash protection comparable to water and LV. Reserve easements for future repairs and adoption – operators increasingly expect the same rights as other utilities. Upcoming Ofgem oversight and technical standards, including the Heat Networks Technical Assurance Scheme, will reinforce this utility-grade approach. - Dwelling internals
A networked GSHP sits inside each home, with various configuration options to connect to a hot water cylinder. Typically fitted beneath a cylinder, you’ll need a full-height cupboard on every house type and as ever, a clear condensate/overflow strategy as per building regs. For heat hubs, plan HIU cupboards near the riser with maintenance clearances and routes for primary pipework. Both approaches benefit from wet heat emitters sized for low flow temperatures, which helps HEM performance and user comfort.
- Acoustic and visual impact
Networked GSHPs move plant indoors and underground, which means no exterior ASHP boxes, fewer acoustic risks and cleaner façades. That can simplify planning on tight plots and preserve streetscape consistency. For community heat hubs, the plant is centralised – your task is then enclosure design, intake/exhaust management and vibration isolation rather than pepper-potting individual units. - Electrical strategy and phasing
Both networked GSHPs and community heat hubs can flatten site peaks, which influences substation sizing and staging. Feed those profiles into the connection application early – a good set of numbers can avoid costly over-specs. Thermal storage in community heat hubs particularly supports time-of-use shifting. Expect operators to ask for roof or plantroom space for tanks that make the whole site connection cheaper. - Compliance and modelling
HEM rewards fabric-first envelopes and low distribution losses. For heat networks, losses in buried mains and risers matter – keep runs short, insulate aggressively, and favour lower network temperatures. The FHS notional specifications for network-connected dwellings underline these levers, so align your details with that logic and capture them in the requirements. - Procurement and adoption
These systems are often delivered “like a utility”: a specialist designs, builds and adopts the ground array, heat pumps or network, then operates under regulated consumer standards. Architects should reflect this in land transfer plans (easements/wayleaves), cupboard sizes, meter cupboard positions, and the O&M access strategy. With Ofgem regulation phasing in from 2026, expect defined rules on metering, pricing transparency and service continuity.
Under the Future Homes Standard, heat is a master planning question. Whether you opt for an ambient loop with in-home GSHPs or a community heat hub, the architectural decisions you lock in now considering space, routes, emitters, and access, will determine not just compliance, but deliverability, affordability and the lived quality of the neighbourhoods you design. The policy direction and regulation are aligning – the practices that treat low-carbon heat as a design driver, not a late-stage service, will be the ones shaping the next generation of UK housing.