Read the spec first
Start with Division 26. Read 26 05 19 for conductors and 26 05 33 for raceways and boxes. Read 26 24 16 for panelboards and 26 51 00 for interior lighting. Note the wiring methods the spec allows. A spec that requires conduit everywhere changes the whole job.
Also read Division 01 for temporary power and the alternates. Skim Divisions 23, 27 and 28 for work that lands on the electrician.
Sheets and schedules that carry the count
- The lighting fixture schedule. It gives each fixture type, lamp, voltage and mounting.
- The panel schedules. They list every circuit and its load.
- The one-line diagram. It shows the service, the gear and the feeders.
- The power and lighting plans on the E sheets.
- The mechanical equipment schedule. It tells you what you must connect.
Steps in order
- List the gear from the one-line diagram: service, switchboards, panels and transformers.
- Measure each feeder. Record the conduit size and the wire size from the feeder schedule.
- Count light fixtures by type, one sheet at a time.
- Count devices: receptacles, switches, sensors and floor boxes.
- Count equipment connections from the mechanical and kitchen schedules.
- Measure branch conduit and wire, or use your own average per device.
- Compare your counts with the panel schedules. Chase every circuit you cannot find.
Count, length, area or volume
- Count: fixtures, devices, panels, disconnects, boxes and equipment connections.
- Length: conduit, wire, cable tray and feeders. Add the vertical runs.
- Area: seldom used. Some estimators check a budget by building area.
- Volume: trench excavation and concrete for duct banks and pole bases.
Conflicts to find, and what to exclude
- The fixture schedule names one maker. The spec lists other makers or none.
- The reflected ceiling plan shows more fixtures than the lighting plan.
- The mechanical schedule and the panel schedule show different voltages for one unit.
- Nobody states who supplies starters, disconnects and variable frequency drives.
- Fire alarm and low voltage show on the E sheets with no spec section.
Qualify utility company charges, temporary power and trenching. Exclude low voltage cable if another contractor carries it. State if you carry raceway only.
Trade takeoffs · Updated 11 Nov 2026