Planning IT Infrastructure for a New Office Buildout: A GC and Tenant Checklist

A new office buildout is exciting, but the network cabling is almost always the piece that gets squeezed. Walls go up fast, the general contractor is focused on framing and finishes, and the low-voltage scope quietly slides to the bottom of the list. Then move-in week arrives and there is nowhere to plug in the phones, the Wi-Fi is patchy, and the server closet is a shared janitor’s space with no power. We have walked into that situation more than once across Chicagoland, and the fix after drywall is always more expensive than doing it right the first time.

Here is the part most tenants miss: in a typical lease, the tenant improvement (TI) allowance often does not cover IT infrastructure, cabling, security systems, or AV. Those usually come out of your own budget, which means you want them planned early and scoped accurately, not discovered as a surprise. This checklist walks through what to nail down, roughly in the order it matters during a buildout.

Start before the walls: the planning phase

The cheapest time to run cable is when the ceiling is open and the studs are bare. That window is short, so the planning has to happen before construction, not during it. Get your low-voltage contractor looking at the floor plan at the same time the architect and GC are finalizing it.

Lock down the floor plan and headcount

• Where will desks, huddle rooms, conference rooms and reception sit, and how many people per area?
• Which rooms need wired connections versus Wi-Fi only? Conference rooms, printers, point-of-sale and AV almost always want a hard line.
• Where do wireless access points go? Open-plan offices and rooms with glass walls or demising walls need more APs than people expect.
• Where will security cameras, card readers and door controllers live? Those are low-voltage runs too, and they are easiest to plan alongside the data cabling.

Every one of those becomes a cable drop. It is far better to over-provision a few drops now than to cut into finished walls later for the one you missed.

The telecom room: your MDF and IDF closets

Every office needs a real home for its network gear. On a single floor that is one main room, often called the MDF (main distribution frame). On multiple floors or a large footprint you add IDF (intermediate distribution frame) closets so no cable run gets too long. This matters because copper Ethernet has a hard limit of about 90 meters for the permanent cable run, plus patch cords. Anything beyond that needs an IDF closet closer to the work area, with fiber tying it back to the main room.

When you mark that closet on the plan, make sure it actually works as a telecom room. The things people forget:

• Dedicated electrical: clean, properly grounded circuits on their own breaker, ideally backed by a UPS. Coordinate this with the electrician early because it is a separate trade.
• Cooling: a closed closet full of switches and a UPS generates real heat. Without airflow or a dedicated mini-split, gear runs hot and fails early.
• Space and a real rack or wall-mount: not a shelf in a coat closet. Leave room to stand in front of the rack and work.
• Plywood backboard and cable tray or J-hooks above the ceiling to carry runs cleanly back to the closet.
• A door that locks. This is your network’s front door.

Getting closet location and power right is where the GC, the electrician and the cabling contractor have to talk to each other. That coordination is the single biggest thing that goes wrong on buildouts, so make someone own it.

Choosing the cabling

For the horizontal runs from the closet out to each desk, AP, camera and phone, Cat6 is the practical standard for most offices, with Cat6a a smart upgrade where you want headroom for 10-gig or longer runs feeding access points. For the backbone between an IDF and the MDF, fiber is the right call: it carries far more bandwidth, runs much longer distances, and gives you room to grow. If you want a deeper comparison, our guide on Cat6 vs. Cat6a breaks down where each one earns its keep.

A few rules of thumb we hold to on every job:

• Run at least two drops to each workstation. The marginal cost of the second cable while the ceiling is open is tiny compared to adding it later.
• Pull dedicated cabling to each wireless access point rather than daisy-chaining off a desk jack.
• Plan for Power over Ethernet (PoE) for phones, cameras and APs so those devices draw power from the switch instead of needing an outlet at every location.
• Leave spare capacity in the conduit, tray and closet. Every office grows.

Label, test and document before go-live

This is the step that separates a clean install from a closet full of spaghetti. Every cable should be labeled at both ends to a consistent scheme, color-coded by function where it helps (data, voice, camera). Then the whole plant gets tested and certified with proper gear, not just a quick continuity check. Certification confirms each run actually meets its rated performance, and it gives you a report you can hand to the next contractor years from now.

Insist on as-built documentation at closeout: a labeled floor plan showing every drop, a port map for the patch panels, and the test results. This is the institutional memory of your network. Without it, the next person to touch the system starts from zero. Structured cabling done this way is the foundation everything else sits on, which is why we treat it as its own discipline; if the term is new to you, see our primer on what structured cabling actually is.

A quick sequence to keep in your back pocket

• Plan the drops, closets and AP locations off the floor plan before construction starts.
• Coordinate closet power, cooling and location with the GC and electrician early.
• Rough-in the cabling while ceilings and walls are open.
• Terminate, label, test and certify everything.
• Stand up switches, Wi-Fi, phones and cameras, then validate before move-in day.

Do it in that order and your move-in week is about setting up desks, not chasing a contractor to fish one more cable through a finished wall.