Estimating, Bidding, and Project Administration
Estimating Essentials
Accurate estimates require takeoffs of pipe, fittings, sprinklers, hangers, and valves. Labor is typically estimated by the foot or by the sprinkler head, adjusted for difficulty. Include overhead, profit, and contingency. Know the difference between direct costs and indirect costs.
Bidding Strategy
Bids must be based on the plans and specifications, with clarifications for ambiguities. Arizona law requires that bids include the contractor's license number. Bid errors can be costly; always review the scope and exclusions.
Project Administration
Once awarded, manage submittals, RFIs, change orders, and schedules. Track costs against the estimate. Document all communications. Closeout requires as-built drawings, warranties, and final payment.
Traps
- Underestimating labor for difficult installations.
- Missing exclusions that lead to disputes.
- Failing to document change orders.
- Not accounting for permit fees and inspection costs.
Worked Example
A 20,000 ft² warehouse with 300 sprinklers: pipe takeoff ~2,500 ft, 300 heads, 150 hangers. Labor at 0.5 hours per head plus pipe installation. Add 15% overhead and 10% profit. Include permit fees and contingency.
Rule of Thumb
Always add a contingency (typically 5–10%) for unforeseen conditions; never bid at cost.