HVAC Takeoff

Supply and return ductwork is measured by size and shape from the mechanical plans, diffusers and grilles are counted per the schedule, and equipment — rooftop units, air handlers, condensers — is quantified with the accessories and controls shown on the drawings.

How we take it off

Ductwork is taken off duct-run by duct-run from the mechanical plan, converting each section's dimensions into sheet metal square footage rather than pricing per linear foot of a nominal size. Diffusers, grilles and registers are counted against the air-device schedule. Equipment is taken from the mechanical schedule with its rated capacity, and controls and accessories (dampers, VAV boxes, thermostats) are counted from the same set rather than assumed.

What the second-estimator review is checking

• Duct sizing changes along a run (transitions, reductions) missed, understating sheet metal square footage
• Flexible duct connections and insulation left off the material list
• Equipment quantities taken from the plan symbol count without confirming against the mechanical schedule
• Controls and dampers bid as an allowance instead of counted from the drawings