Division 27 was created in the 2004 edition of MasterFormat, when communications work was split out of the old Division 16 – Electrical. Older specifications and some owners still lump it in with electrical, so check how your bid documents are organized.
What's included in Division 27
| Section group | Title | Typical scope |
|---|---|---|
| 27 05 00 | Common Work Results for Communications | Pathways, grounding and bonding, sleeves, firestopping of penetrations, labeling |
| 27 10 00 | Structured Cabling | Copper and fiber backbone and horizontal cabling, patch panels, racks, outlets |
| 27 20 00 | Data Communications | Network equipment such as switches and wireless access points (often owner-furnished) |
| 27 30 00 | Voice Communications | Telephone systems and voice equipment |
| 27 40 00 | Audio-Video Communications | Conference room AV, displays, projection, sound systems |
| 27 50 00 | Distributed Communications and Monitoring | Paging, intercom, nurse call, clock systems, DAS |
What is NOT in Division 27
- Fire alarm, access control, CCTV and intrusion detection are in Division 28 – Electronic Safety and Security.
- Power to equipment racks and AV is in Division 26 – Electrical.
- Building automation and controls are in Division 25 – Integrated Automation, or in Division 23 for HVAC controls.
How to estimate Division 27
Low-voltage takeoffs are count-heavy. Most of the cost sits in the number of drops and the length of each cable run.
- Count outlets and drops. Use the technology (T-series) plans and the outlet legend. Note how many cables each outlet type carries: a typical workstation might be two data drops; a wireless access point one or two.
- Locate telecom rooms. Every horizontal cable runs back to a telecom room or main distribution frame. Mark them on the plans.
- Measure average runs. Measure the cable path from each area to its telecom room, add vertical drops and slack, and stay within the 90-meter limit for horizontal copper runs.
- Price backbone cabling. Fiber and copper backbone between telecom rooms and floors is measured separately.
- Add rooms and racks. Racks, cable managers, patch panels, ladder rack and grounding busbars for each room.
- Add support systems. J-hooks, cable tray, sleeves and firestopping where cables cross rated walls.
- Add labeling, testing and certification. Most specs require every cable to be tested and certified, with a report at closeout.
Common mistakes
- Missing the cable count per outlet type (one symbol, but four cables)
- Pricing pathways that the electrical contractor is already carrying, or the opposite
- Forgetting AV and paging scopes that appear only in the specifications
- No allowance for after-hours work in occupied buildings
- Owner-furnished equipment priced as contractor-furnished
Get a Division 27 estimate
Premium Estimating prepares Division 27 takeoffs for low-voltage contractors, electrical contractors and GCs. You receive device counts, cable footage by type, room equipment and labor in Excel, with marked-up plans. See our Division 27 page or send us your plans.
Need a number you can bid from? Send us your plans for a quote, or see our pricing.