Plan Reading, Estimating, and Project Documentation
Documents you must read
A set usually includes floor plans, one-line diagrams, risers, panel schedules, details, and specifications. Learn the symbol legend and the scale before counting anything. Division 26 specifications control submittals, testing, and closeout. A panel schedule names circuits; a one-line shows distribution, ratings, and fault current.
Estimating basics
- Takeoff: measure or count each item, then add connectors, supports, and waste, typically 3 to 10 percent depending on material.
- Labor units convert quantity to hours; add supervision, permit fees, and contingency.
- Submittals, shop drawings, and product data precede installation and need review time.
- An RFI asks for clarification; a change order changes price or time. Keep them separate.
Worked example
A plan at 1/8 in. = 1 ft 0 in. shows a homerun measuring 3 1/2 in. on paper. 3.5 × 8 = 28 ft, plus 10 ft for terminations above the ceiling and at the panel, plus 10 percent waste gives about 42 ft of conduit. At 1/4 in. scale the same measurement would be 14 ft, so checking the scale first prevents a 100 percent quantity error.
Traps
- Measuring without checking the scale or a graphic bar.
- Omitting homeruns, make-up, and supports from the takeoff.
- Pricing an RFI response as a change order without written direction.
- Failing to record as-built changes for the closeout package.