Div 27 & 28 Scope Guide: What's Yours vs the Electrical Sub's
If you're a low voltage, security, fire alarm, or AV contractor, scope splits are one of the easiest places to lose money on a bid. Your work lives in Divisions 27 and 28, but pieces of it often show up in the electrical sub's scope too, and the lines change from project to project. Here's what you typically carry, where the overlaps happen, and how to catch problems before bid day.
Division 27: Communications
Structured cabling, telecommunications infrastructure, and the pathways and terminations for voice and data systems.
Division 28: Electronic Safety and Security
Access control, video surveillance, intrusion detection, and fire detection and alarm systems.
Where the electrical sub comes in
On many projects, the electrical contractor carries rough-in for your systems: conduit, backboxes, sleeves, and backboards. On others, you carry it yourself. The specs decide, and they don't always say it clearly.
Where the gaps happen
The same system can show up in more than one place. Fire alarm devices may be specified in Div 28 while their conduit and backboxes sit with the electrical sub. Head-end equipment may be owner-furnished. If you assume the electrical sub carries rough-in and they assume you do, nobody prices it. If you both price it, you're double-counting and losing the job on number.
How to protect your bid
- Read the electrical specs before pricing, not just Divisions 27 and 28.
- Mark every item as yours, the electrical sub's, or owner-furnished.
- List your assumptions and exclusions clearly in your proposal.
- Send an RFI before bid day when the split is unclear.
Catch scope splits automatically
BidSignal flags scope split risks on every invitation to bid, so you know what's yours before your estimator opens the drawings.