What Does a Duct Takeoff Service Do?
You send the bid set and the service sends back quantities. Someone on their side goes sheet by sheet, scales every duct run, counts every fitting and air device, and builds the list. A good service marks up the drawings in color so you can see what was counted and what was left out.
Turnaround is quoted in days, and it depends on the size of the set and how many other jobs are ahead of yours. A duct takeoff service stops at quantities. Duct estimating services go further and add material pricing, labor and markup, which means another firm's rates sitting inside your number.
What to Send With the Drawings
Most bad takeoffs start with a partial package, so send all of this:
- The full mechanical set, including sections, details and schedules, not only the floor plans
- The HVAC specification (Division 23 in MasterFormat), which sets duct material, pressure class, sealing and insulation
- Every addendum, so the takeoff is done on the current sheets
- Your scope: which systems you carry, and whether insulation, grilles, dampers and hangers are in or out
- The format you want back, so the quantities drop straight into your estimate
What to Check Before the Quantities Go Into Your Bid
A takeoff you didn't build still has your name on the bid, so spot-check it. Pick two sheets and recount one system yourself. If your count and theirs are close, the rest is probably sound, and if they aren't, ask how they measured before you use any of it.
Then check these against the drawings and the specification:
- Gauges follow the pressure class in the specification, not a default gauge for every size
- Fittings are counted by size, not lumped into an allowance
- Fire and smoke dampers match the life safety sheets, not only the mechanical plans
- Duct shown on other trades' sheets (kitchen exhaust, rooftop units, architectural details) made it into the count
- Insulation is split by duct type, since supply, return and outside air often take different wraps
Duct Takeoff Service vs. an In-House Takeoff
| Takeoff Service | In-House Estimator | |
|---|---|---|
| Who builds the count | Someone outside your company | Your own estimator |
| Knows your crews and fittings | No | Yes |
| Turnaround | Days, depending on their queue | Days, depending on your bid board |
| Who checks it | You, before it goes in the bid | You, before it goes in the bid |
Either way, the estimator owns the number that goes in the bid. A service adds hours to your bid board without adding headcount, and you still have to check what comes back.
How The Takeoff AI Does a Duct Takeoff
The Takeoff AI reads the mechanical drawings and runs the duct takeoff end to end. It measures every duct run, counts the fittings, dampers and air devices, and counts the gaskets, bolts and welds that go with them. You get the material takeoff (MTO) and the labor takeoff (LTO) together, priced into a bill of materials (BOM), plus a 3D model of the duct runs built from the 2D sheets.
It is trained on more than 1 million HVAC drawing sets and runs at 95% accuracy. Every quantity is highlighted on the sheet it came from, with an accept or reject option on each item, so the estimator checks the count instead of building it. 113 estimators say The Takeoff AI is the best duct takeoff platform they have used, and it helps them estimate projects in 3 to 4 hours that once took 40 to 50 hours.
