Where the disconnect typically happens

On most commercial construction and fit-out projects, IT infrastructure is treated as a late-stage specification. The architect draws the space, the M&E consultant designs mechanical and electrical services, and IT gets bolted on once the shell is mostly resolved. By that point, the decisions that matter most – where the comms room goes, how cable routes will run, where outlets need to be – have already been made by people who weren't thinking about IT at all.

The result is a set of drawings that don't reflect reality. Comms rooms positioned in corners with no cable management headroom. Data outlets on walls that furniture will cover. Cable routes that conflict with ductwork or structural beams with no clear alternative path. These aren't edge cases – they're the norm on projects where IT isn't brought in early.

The cost of fixing them scales dramatically depending on when they're caught. A change to a cable route at RIBA Stage 2 costs a line on a drawing. At Stage 5, when construction is underway and ceilings are closed, it costs cutting into completed fabric, rescheduling other trades and revisiting work that was signed off weeks ago.

What IT infrastructure requirements need to be in the design drawings

IT infrastructure isn't a single specification item – it's a set of interdependent requirements that touch almost every aspect of a building's design. The drawings need to capture all of them clearly enough that every trade knows what they're working around.

At a minimum, the design drawings need to show:

These elements need to be confirmed before structural or M&E design is finalised. Once concrete is poured or ductwork is fixed, the flexibility to accommodate IT requirements without cost penalty disappears.

Cable routes, containment and service coordination

IT cabling has to get from the comms room to every part of the building. The path it takes – through risers, ceiling voids, floor ducts and wall chases – needs to be planned as carefully as any other service route. On projects where it isn't, the installation team arrives to find every logical path blocked.

HVAC ductwork is the most common obstruction. Mechanical engineers size their ductwork to the space available in ceiling voids, and when IT isn't represented in the coordination process, data cables end up competing for the same routes. The same applies to structural beams, sprinkler systems, fire barriers and lighting track – all of which can sever a planned cable route without anyone from IT having been consulted.

The solution is services coordination – a formal process of overlaying each trade's design on a shared set of drawings to identify and resolve clashes before installation. IT containment needs to be represented in that process as a named service, with defined routes, minimum bend radii and separation requirements from power cables. Without that, IT gets squeezed into whatever space is left.

Containment also needs to be specified correctly. Cable tray, basket tray, conduit and floor duct all serve different purposes and have different installation requirements. Specifying the wrong containment type in the drawings creates problems later – either for the IT installer trying to work with an incompatible system, or for the M&E contractor who's priced against a different spec.

Comms room position, size and services

Comms room positioning is one of the most consequential decisions in the design of any connected building, and it's routinely made without IT input. The result is rooms that are too small, in the wrong location, or poorly served by power and cooling.

A comms room needs to be within reach of the network cabling it serves – the standard maximum cable run from an active switch to an outlet is 90 metres, which defines how many areas a single room can serve and where satellite comms spaces may be needed. Position the room in the wrong part of the floor plate and you either exceed cable length limits or end up running cable in ways that create additional coordination problems.

Size matters more than it might appear. The room needs to accommodate racks at the density the design requires, with sufficient front and rear clearance for installation and maintenance access. It also needs to account for cable management – the volume of cable entering and leaving a comms room is substantial, and rooms that are sized purely to the rack footprint leave no room to manage it.

Power and cooling are specified by the electrical and mechanical teams, but only if IT has communicated its requirements. A comms room with inadequate cooling will experience equipment failures. A room without a reliable UPS feed creates a single point of failure for the whole building's network. These aren't IT problems – they're building design problems that need to be resolved at the right stage.

Power and data outlet schedules

The outlet schedule – the list of every data and power outlet in the building, its position and its type – is one of the most practically important documents in an IT design. It's also one of the most frequently wrong.

Architects often include a generic outlet count on drawings that doesn't reflect how the space will actually be used. A desk position marked with two data outlets and two power sockets sounds reasonable until you consider that modern desk setups – including docking stations, monitors and IP phones – can require four or more power outlets per position. Meeting rooms with generic "data point" notations don't account for display connections, video conferencing equipment, wireless access point positioning or room booking systems.

The outlet schedule needs to be built from operational requirements, not architectural convention. That means understanding how each space will be used, what equipment will be in it and what connectivity each device needs. It also means thinking about what isn't visible – access control readers, IP cameras, door entry systems and building management system sensors all require network connections that won't appear on a furniture layout.

Once the outlet schedule is agreed, it needs to be on the drawings in a form that every trade can read and act on. Data outlet positions inform the cable routing design. Power outlet positions need to match the electrical design. If they don't align, you get installation teams working to different information – which is where expensive on-site changes originate.

Coordinating with the design team

IT infrastructure sits at the intersection of architecture, structural, mechanical and electrical design. That means IT requirements need to be communicated to, and coordinated with, all of those disciplines – not just the architect or the IT contractor.

In practice, this means attending design team meetings, reviewing the full set of drawings (not just the IT-specific ones) and raising clashes formally through the project's standard coordination process. It means producing IT drawings that are compatible with the project's CAD standards so they can be overlaid and checked against other services. And it means being responsive to design changes – when a partition moves, an IT drawing may need to be updated to match.

IT infrastructure should be on its own CAD layers – typically separated into at least containment, outlet positions and comms room design. Keeping these on discrete layers means the design team can overlay IT against any other service and check for conflicts without having to read a combined drawing that shows everything at once. It also makes it straightforward to issue IT-only drawing revisions without reissuing the full set.

When to bring in an IT infrastructure specialist

The RIBA plan of work sets out a clear framework for when decisions need to be made. IT involvement should start at Stage 2 – concept design – when the fundamental spatial decisions are still open. That's when comms room positioning, primary cable routes and the overall infrastructure strategy need to be established.

Stage 3 is where the detailed IT design should be developed alongside the rest of the technical design. By the time the project reaches Stage 4, the IT drawings should be complete enough to be coordinated against all other services and included in the tender package. Stage 5 shouldn't involve any significant IT design decisions – only installation of a design that's already been resolved.

Projects that bring IT in at Stage 4 or Stage 5 will almost always encounter problems that could have been avoided. The design team is under delivery pressure, changes are costly and the tolerance for additional coordination work is low. The IT contractor ends up designing around constraints rather than to a proper brief.

Bringing in a specialist at Stage 2 doesn't add complexity to the design process. It removes it – because the questions that would otherwise surface during installation are answered in the drawings before anyone picks up a drill.

What good IT design drawings look like

Good IT design drawings are clear, coordinated and buildable. They show exactly what needs to be installed, where it goes and how it connects – in enough detail that a competent installer can work from them without needing to make decisions on site.

That means dimensioned comms room layouts showing rack positions, cable management and access clearances. Floor plans with outlet positions annotated to the outlet schedule. Containment route drawings showing primary routes, secondary routes and the level at which containment runs. A riser diagram showing how the building's network infrastructure connects vertically across floors.

The drawings also need to be issued at the right revisions and cross-referenced against the rest of the design package. A set of IT drawings that's one revision behind the architectural drawings isn't just unhelpful – it actively creates risk, because installers may work from outdated information.

Finally, good IT design drawings are produced by someone who understands both IT infrastructure and construction process. The technical knowledge to design a network is necessary but not sufficient. The ability to translate that design into buildable drawings, coordinate it against other trades and manage it through a live design process is what separates an IT design that works from one that creates problems on site.

Route B provides IT design and CAD services for commercial and hospitality developments, working alongside architects and M&E consultants. Get in touch.