Contracting, Estimating, Bidding, and Project Administration
Documents that define the deal
Bids rest on the drawings, specifications, addenda, and pre-bid clarifications. Read addenda before pricing - they change scope. A complete proposal states inclusions, exclusions, allowances, schedule, payment terms, and the basis of price. Residential work requires a written contract with the required disclosures, and home solicitation sales carry a three-day right to cancel.
Takeoff and pricing
Estimate by system: equipment, refrigerant line sets, ductwork by pound or square foot, fittings, controls, permits, crane or rigging, disposal, and startup. Apply labor units (hours per ton, per register, per braze) and adjust for height, occupied space, and access. Add project overhead, then margin. Price change orders in writing before doing the work.
Administration
Track submittals and shop drawings, RFIs, the schedule of values, stored materials, and monthly progress payments. Protect lien rights - New Mexico deadlines are strict, and a missed notice or recording date can void the claim. Close out with punch list, as-builts, O&M manuals, warranties, and owner training.
Worked example
Replace a 3-ton split system: equipment $3,200, materials $1,100, labor 16 hours at $85 = $1,360, permit $150, disposal $75, freight $60. Direct cost = $5,945. With 15 percent overhead and 10 percent net, price = 5,945 / (1 - 0.25) = $7,927. A 15 percent markup gives $6,837 whose 13 percent gross margin does not even cover the 15 percent overhead.
Traps
Bidding without reading addenda; omitting permits, crane, or electrical; vague exclusions; no written change orders; front-loading the schedule of values.