Building Regs Part R: In-Building Physical Infrastructure for High-Speed Broadband in New Builds

Quick Answer: Approved Document R, Requirement R1, requires new dwellings (and buildings undergoing major renovation) in England to be built with in-building physical infrastructure capable of carrying high-speed (gigabit-ready) broadband — essentially a duct/cable route from the property boundary to a network termination point inside, plus a sensible position for the router. A later amendment, R2, requires that where a gigabit-capable network is available, the building is actually connected to it, subject to a cost cap of £2,000 per dwelling. It is a build-quality requirement checked by Building Control, not a telecoms licence matter.

Summary

Part R is the newest and smallest of the Approved Documents, but it matters because retrofitting broadband infrastructure into a finished building is expensive and disruptive. The idea is simple: build the physical pathway for fibre into the home at first fix, so a broadband operator can connect the property cheaply later without digging up driveways or chasing walls.

There are two requirements. R1 (in-building physical infrastructure) applies to new dwellings and to buildings undergoing major renovation work, and requires the ducts, conduits, and a network termination space that a gigabit-capable connection would need. R2 (connection to a gigabit-capable network) is the later upgrade: where such a network is available near the site, the developer must actually arrange the connection, up to a cost cap per dwelling. Above the cap, the developer must install infrastructure to the next-best available network instead.

For tradespeople — particularly groundworkers, electricians, and data cabling installers on new build — Part R means planning a duct route from the boundary, an entry point into the building, a draw-string or installed cabling run to a termination point, and a router position near the consumer unit with power and a clear cable route. It overlaps with structured data cabling work but is a distinct Building Regulations requirement. Get the duct in before the slab and the screed go down; chase it in afterwards and the cost multiplies.

Key Facts

• Approved Document R (2022 edition) — the current version requiring gigabit-ready infrastructure. Applies to building work where the building notice / full plans / initial notice was given on or after 26 December 2022.
• Requirement R1 — in-building physical infrastructure — new dwellings and buildings undergoing major renovation must have physical infrastructure (ducts, conduits, network termination space) capable of carrying high-speed electronic communications networks (gigabit-capable).
• Requirement R2 — connection to a gigabit-capable network — where a gigabit-capable network is available, the new dwelling must be connected to it, subject to a per-dwelling cost cap.
• £2,000 cost cap — the per-dwelling cap on the cost of connecting to a gigabit-capable network under R2. Above the cap, install infrastructure for the highest-speed network that can be provided within the cap.
• "Gigabit-ready" — infrastructure capable of supporting connections of 1 Gbps and above, primarily Fibre to the Premises (FTTP).
• Major renovation — defined as renovation work to more than 25% of the surface area of the building envelope, which triggers R1 for the renovated building.
• Network termination point — a fixed location inside the dwelling where the operator's connection terminates; the router / Optical Network Terminal (ONT) sits here.
• Router position — ADR expects a sensible, accessible position for the broadband router, typically near the electrical consumer unit, with a power socket nearby and a clear cable route to living spaces.
• Duct from boundary — the in-building infrastructure connects to a point at or near the property boundary so an operator can join their network to the duct without entering the building structure.
• Conduit/duct sizing — ducts should be sized and routed to allow a fibre to be pulled through (draw cord) without excessive bends; tight 90° bends and crushed flexible conduit are the common failure points.
• Buildings other than dwellings — Part R also applies to certain new commercial buildings and to mixed-use developments containing dwellings.
• Not a competent-person scheme — Part R compliance is demonstrated to Building Control; there is no FENSA-style self-cert route specific to Part R.
• Relationship to data cabling — Part R is about the physical pathway and connection; the internal structured cabling (Cat6/Cat6A, TV, etc.) is good practice and often installed at the same time but is a separate scope.
• BS EN 50173 / BS EN 50174 — the structured cabling and cabling installation standards referenced for in-building communications infrastructure.

Quick Reference Table

Detailed Guidance

What "in-building physical infrastructure" actually means on site

R1 is satisfied by providing the empty pathway (and termination space) that a gigabit connection needs — you are not obliged to install the operator's fibre yourself, only to make it cheap for them to do so later. In practice that means:

1. A duct or conduit from the property boundary (where the operator's network reaches) into the building.
2. A clear, low-bend route from the entry point to a network termination point inside.
3. A termination space at that point — typically a small enclosure or position near the consumer unit — where the operator's ONT/router will live.
4. A draw cord left in the duct so a fibre can be pulled through later without re-opening the run.

The two cheap-to-get-wrong details are bend radius and burial depth. A fibre cannot negotiate sharp bends, so use sweeping bends and avoid crushed flexible conduit. External duct from the boundary must be buried at a sensible depth and capped to keep water and grit out before connection.

R2 — connection, and the cost cap

R2 goes a step further than just the pathway. Where a gigabit-capable network is available at the site, the developer must arrange for the dwelling to be connected to it. This is subject to a cost cap of £2,000 per dwelling:

• If connection costs at or below the cap → connect to the gigabit network.
• If connection costs above the cap → the developer instead installs infrastructure to support the highest-speed network that can be connected within the cap, and provides the gigabit-ready in-building infrastructure (R1) regardless.

"Available" is judged at the time of the work — if no gigabit network reaches the area yet, R1 (the pathway) still applies so the home is ready when one arrives.

Coordinating Part R with first fix

The cheapest time to satisfy Part R is before the floor slab, screed, and plasterboard go on:

• Groundworks: lay the boundary-to-building duct in the same dig as the other services, with the duct entering above DPC and sealed against water ingress.
• Electrical first fix: position the network termination near the consumer unit, run a draw-corded conduit to it from the entry point, and provide a switched socket for the router.
• Data cabling (good practice, separate scope): run Cat6/Cat6A from the termination point to a structured wiring position so the home can distribute the connection internally.

Chasing a duct into finished blockwork and re-screeding a floor to add a missed run is exactly the cost Part R exists to avoid.

Devolution note

Part R is an England Approved Document. Wales has its own building regulations regime and its own approach to broadband infrastructure; Scotland uses the Technical Handbooks (separate standards); Northern Ireland uses its own Technical Booklets. The gigabit-ready policy direction is similar across the UK, but cite the correct national document for the project location — do not quote Approved Document R on a Scottish or Welsh job.

Frequently Asked Questions

Do I have to install the actual fibre, or just the duct?

For R1 you provide the physical infrastructure — the duct/conduit pathway, draw cord, and termination space — not the operator's fibre itself. The broadband operator pulls their fibre through later. For R2, where a gigabit network is available and within the cost cap, the dwelling must actually be connected — so the connection has to be arranged, though typically by/with the operator rather than as a cabling task for the general builder.

Does Part R apply to extensions and loft conversions?

R1 is triggered by new dwellings and by major renovation (renovation affecting more than ~25% of the building envelope). A modest extension or a loft conversion that does not cross the major-renovation threshold generally does not trigger Part R, though running a duct/data route while the walls are open is sensible. Always check the specific scope against the major-renovation definition.

What is the £2,000 cap and who pays?

The cap of £2,000 per dwelling limits how much the developer must spend to connect the dwelling to a gigabit network under R2. If connection costs more than the cap, the developer is not required to fund the gigabit connection but must still provide the gigabit-ready in-building infrastructure (R1) and connect to the best network achievable within the cap. The developer bears the cost up to the cap.

Where should the router go?

Part R expects an accessible, sensible position for the router/ONT — in practice near the electrical consumer unit, with a switched socket and a clear cable route into the living areas. Avoid a cupboard buried deep in the floor plan with no power and no onward cabling; that defeats the purpose.

Is Part R the same as needing planning permission for broadband?

No. Part R is a Building Regulations requirement enforced by Building Control as part of the build. It is separate from any planning permission and from the telecoms operators' own statutory powers to install networks. They can overlap on a site but are different regimes.

Regulations & Standards

• Approved Document R (2022 edition) — Physical infrastructure for high-speed electronic communications networks; Requirements R1 (in-building infrastructure) and R2 (connection to a gigabit-capable network).

• Building Regulations 2010 (as amended) — the legal basis; Requirement R is in Schedule 1.

• BS EN 50173 — Information technology — generic cabling systems (structured cabling design).

• BS EN 50174 — Information technology — cabling installation (planning, practice and inspection of installed cabling).

• The Building etc. (Amendment) (England) Regulations 2022 — the amending instrument that introduced the gigabit-ready Part R requirement and the cost cap; in force 26 December 2022.

• GOV.UK — Approved Document R (physical infrastructure for high-speed electronic communications networks) — full text of ADR.

• GOV.UK — Building gigabit-ready new homes guidance — policy and cost-cap explanation.

• Planning Portal — Building Regulations Part R — practical overview.

• legislation.gov.uk — Building Regulations 2010 — the principal regulations as amended.

• part r broadband — companion article on gigabit-ready infrastructure and cable routing for new dwellings.

• data cabling — internal structured cabling (Cat6/Cat6A) that distributes the connection inside the home.

• building regs overview — how Part R fits among the Approved Documents.

• part s ev charging — Part S, the other newly added Approved Document also coordinated at first fix.