Approved Document R (Broadband Infrastructure): What Homeowners Need to Know

Part R requires that new buildings and buildings undergoing major renovation include in-building physical infrastructure that allows high-speed electronic communications equipment to be installed or upgraded without major structural work.

In practice this means:

• A network termination point — an accessible internal point where the broadband connection enters the building
• Cabling or ducting routes — internal pathways from the network termination point to accessible points within each dwelling, allowing fibre or other cabling to be run without opening walls or floors

The requirement is for passive infrastructure — the ducting and termination points — rather than for actual broadband equipment to be installed. The aim is to ensure the building is ready to accept a gigabit-capable connection whenever the occupant wishes to take one, without the cost and disruption of drilling through walls or floors at a later date.

Part R of the Building Regulations applies to:

• New dwellings — any new house, flat, or other residential building requires gigabit-ready passive infrastructure
• Major renovations — defined as works that touch more than 25% of the building envelope (walls, roof, and floor in contact with the ground). This is not triggered by a typical single-storey rear extension, but a whole-house refurbishment or large-scale conversion may qualify
• Multi-dwelling developments — blocks of flats and housing developments have additional requirements around shared infrastructure and access points
• Conversions to residential use — converting a commercial building, barn, or other structure to residential use where the work constitutes a major renovation

Part R does not apply to:

• Standard extensions or loft conversions where less than 25% of the building envelope is being altered
• Internal alterations that do not involve the building envelope
• Existing dwellings where no major renovation is being undertaken

The term "major renovation" in the context of Part R means works that affect more than 25% of the surface area of the building envelope. The building envelope includes external walls, the roof, and the ground floor — essentially the elements that separate the conditioned interior from the outside.

For a typical terraced house with 80 square metres of total envelope surface, you would need to be altering more than 20 square metres before the major renovation threshold is crossed. A standard rear extension adds to the building but does not necessarily involve alterations to the existing envelope at that scale.

If you are unsure whether your project crosses the threshold, your architect or building control surveyor can advise. The calculation must consider the total works being carried out, not just individual elements — so a project involving new external cladding, roof replacement, and floor insulation across the whole house would likely qualify.

The phrase "gigabit-ready passive in-building physical infrastructure" refers to the ducting, conduit, and entry points that allow a gigabit-capable cable (such as fibre optic) to be routed through the building — not the active equipment (router, ONT, switches) that processes the connection.

For a new house, typical compliance involves:

• A duct from the boundary of the plot to the building (often shared with the developer or network operator)
• An entry point (bushing) through the external wall at an accessible location
• A network termination box on the internal wall at the entry point
• Conduit runs to the main communications point within the dwelling (often adjacent to the consumer unit or in the understairs cupboard)
• An accessible draw-point or outlet at the point of use

The specific design will depend on the building and the network operator involved. Building control will confirm compliance at inspection stage.

Barn conversions and other change-of-use projects to residential often involve works that constitute a major renovation under Part R — particularly where the entire envelope is being insulated, re-roofed, and re-windowed as part of the conversion. In these cases, gigabit-ready passive infrastructure must be incorporated in the design.

This is worth discussing with your architect at an early stage, because retrofitting ducting through finished walls and floors is significantly more expensive than installing it during construction. The cost of including a basic conduit and termination point during construction is modest — typically a few hundred pounds — compared to the disruption of adding it afterwards.

For remote rural properties where gigabit broadband is not yet available, Part R still requires the passive infrastructure to be in place. The provision is forward-looking: it ensures the building will be ready when the network reaches the area.

The Part R requirement is linked to the UK Government's ambition for nationwide gigabit-capable broadband coverage, and sits alongside the Electronic Communications Code (ECC), which regulates how network operators can access land and buildings to install and maintain infrastructure.

For multi-dwelling buildings and large housing developments, Part R requires not just in-building infrastructure but also a suitable common access point that allows network operators to connect their equipment without needing to negotiate access separately with each resident. This is particularly relevant for housing developers, but homeowners building a single new dwelling do not need to worry about the multi-operator aspects of the code.

Building control will check Part R compliance as part of the standard building regulations process for applicable projects. Compliance is typically demonstrated by:

• Design drawings showing the planned infrastructure route, termination point, and cable pathways
• Specification of conduit type and diameter (typically 40mm smooth bore conduit for external ground ducts; smaller for internal routes)
• On-site inspection to confirm the infrastructure has been installed before walls or floors are closed up

There is no specific approved product or certification required — the requirement is performance-based. The infrastructure must be capable of supporting the installation of a gigabit-capable cable without structural alteration. Building control guidance notes and the Approved Document provide more detailed technical specifications for different building types.