Division 27 (Communications)
The CSI MasterFormat specification division covering communications: structured cabling, backbone, Wi-Fi, DAS, AV, and related pathways.
What is Division 27 (Communications)?
Division 27 is the section of the CSI MasterFormat spec book that governs communications systems. On a set of construction documents it covers structured cabling (27 15 00), backbone cabling (27 13 00), wireless and DAS (27 53 00), and audiovisual (27 41 00), plus the pathways and grounding that support them. Anything that carries data, voice, or AV signal generally lands in Division 27, while life-safety and electronic safety systems land in Division 28. Understanding the split matters at bid time: GCs frequently issue 27 and 28 as one low-voltage package, and a bidder who prices only one division will look artificially cheap and get the job for the wrong reasons.
Frequently asked questions
Published references
Use the current project documents and adopted code. These links identify the standards owner, regulator, or manufacturer behind this article.
Where EIG PRO uses this
Related terms
Structured Cabling
The standardized cabling infrastructure (Cat6/6A, fiber) that supports networking, voice, video, and low-voltage devices.
Division 28 (Electronic Safety & Security)
The CSI MasterFormat division covering access control, video surveillance, intrusion detection, and electronic life-safety systems.
BICSI / RCDD
The professional body and credential for structured cabling and ICT design.
TIA-568
The structured cabling standard defining cable types, connectors, and topology.