Telecom Room Sizing & Build-Out
The TIA-569 telecom room requirements: minimum room dimensions by the floor area served, and the build-out rules — backboard, environment, door, lighting, power, and dedicated use. Voluntary-standard values that owner specs routinely tighten; where a spec and this chart differ, the spec governs the bid.
Room size by serving area
| Serving area | Room size | (metric) |
|---|---|---|
| ≤ 5,000 sq ft | 10 × 7 ft | 3.0 × 2.2 m |
| 5,000–8,000 sq ft | 10 × 9 ft | 3.0 × 2.8 m |
| 8,000–10,000 sq ft | 10 × 11 ft | 3.0 × 3.4 m |
Build-out requirements
| Aspect | Requirement |
|---|---|
| How many rooms | Minimum one TR per floor; add another when the serving area exceeds 10,000 sq ft or any horizontal run would exceed 90 m |
| Backboard | ¾-in A-C plywood, 8 ft high, on at least two walls (owner specs often require all four) |
| HVAC | Dedicated, 24/7/365; positive pressure with minimum one air change per hour |
| Temperature | 64–75 °F, 30–55% RH (newer editions allow to 80 °F) |
| Door | 36 in wide × 80 in high minimum, no sill, opens outward (or slides), lockable |
| Lighting | Minimum 500 lux (50 fc), fixtures ≥ 8.5 ft AFF |
| Ceiling | No drop ceiling; minimum 8 ft (8.5 ft commonly specified) |
| Power | Minimum two dedicated non-switched 120 V 20 A receptacles, each on its own branch circuit |
| Dedicated use | No foreign piping or ductwork through the room, no storage, no carpet; surfaces sealed against dust |
Estimating the room, not just the racks
The TR line items that get missed on bids are exactly the ones in the second table: the plywood (fire-retardant, painted with the grade stamps visible — inspectors check), the dedicated circuits, the door hardware, and the grounding busbar with its bonding backbone (see the grounding & bonding chart). Rack layout inside the room follows the rack dimensions chart, and the 90 m rule that forces a second room is the same one behind the distance limits.
Common questions
How big does a telecom room need to be?
By serving area: 10×7 ft up to 5,000 sq ft served, 10×9 ft to 8,000, and 10×11 ft to 10,000 — with at least one room per floor, and another whenever the serving area passes 10,000 sq ft or any horizontal run would exceed 90 m. These are TIA-569 minimums; racks, PDU clearances, and growth usually argue for more.
What are the requirements for a telecom room build-out?
¾-inch A-C plywood 8 ft high on at least two walls (many owner specs say all four), dedicated 24/7 HVAC with positive pressure, a 36-inch outward-opening lockable door with no sill, 500 lux of lighting, no drop ceiling, at least two dedicated non-switched 20 A circuits, and nothing foreign passing through — no piping, no ductwork, no storage. Each item exists because its absence has flooded, cooked, or cluttered someone's cross-connect.
Why can't the telecom room have a drop ceiling?
Because the space above a drop ceiling hides pathways from inspection, invites foreign trades into the room's airspace, and complicates firestopping at the room boundary. TIA-569 prohibits false ceilings in TRs outright — cable trays and sleeves stay exposed and auditable.