HVAC Takeoff for General Contractors Checking Mechanical Bids
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The sample is a real DuctIQ takeoff workbook: no signup. Plans and credits are on the pricing page.
When three mechanical subs bid the same drawings and their numbers sit far apart, the duct scope is usually where the gap hides. One sub carried the exhaust risers, one missed a floor of branch duct, one priced the wrong gauge. A general contractor rarely has an HVAC estimator on staff to find out which, and bid day does not leave time to hire one.
DuctIQ gives a GC or owner's rep an independent duct takeoff from the same mechanical PDF the subs used. Upload the drawings, and the software measures the ductwork at scale and returns footage by system and size, fittings counted and equipment read from the schedules. Every line points back to the sheet it came from, so you can put a specific question to a sub instead of a vague one.
Why mechanical bids are hard for a GC to level
Most trades can be sanity-checked with a unit rate and a floor area. Ductwork resists that. The cost depends on how many linear feet of each size the design calls for, how many fittings sit in those runs, what gauge the sizes and pressure class require, and how much of it is insulated or lined. Two subs can read the same set and land far apart because one counted the fittings and the other folded them into a rate.
Without your own quantities you end up comparing totals and asking each sub to confirm their scope. That rarely surfaces a missed riser or a double-counted floor. Quantities you can point at do.
What you get from the drawings
DuctIQ reads the mechanical plan sheets in the PDF and returns a structured takeoff you can open in Excel:
- Duct linear feet by system (supply, return, exhaust) and by size, with round and rectangular kept apart.
- Fittings counted as their own lines: elbows, tees and taps, reducers and transitions.
- Equipment, diffusers and grilles read from the schedules by tag.
- Gauge per line, with the SMACNA minimum shown and labelled where the drawing does not give one.
- A source sheet on every line, and a Confidence level that flags the reads worth a second look.
Download a sample takeoff (Excel)See the export columns
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Using the takeoff to level and question bids
The point is not to replace your subs' estimates. It is to know which questions to ask before you carry a number.
| What you see | What to ask the sub |
|---|---|
| A sub's duct footage well below yours on one system | Did you carry the full exhaust or return scope shown on the plans? |
| Fitting counts missing or bundled into a rate | How many fittings did you price, and at what allowance? |
| Gauge or lining that differs from the takeoff | Which pressure class and spec section did you price to? |
| Equipment count that does not match the schedule | Which tags are in your number, and which are by others? |
| One floor or area much lighter than the rest | Did you take off every plan sheet, or scale up from a typical floor? |
A takeoff gives you specific, sheet-referenced questions. The sub still owns their price.
What DuctIQ does not do for a GC
DuctIQ is an HVAC ductwork takeoff, not a full mechanical estimate. It does not price labour, take off piping or plumbing, or judge a sub's means and methods. It reads 2D mechanical PDFs, so a drawing without a readable scale or with duct sizes missing will come back with those lines flagged rather than guessed.
Detail sheets, schedules and legends are used to resolve tags and attributes, not measured again, so the footage reflects the plan views only. That is the same discipline a mechanical estimator follows to avoid double counting.
How to try it on a job you are bidding now
Pick a set where the mechanical numbers already look uneven. Upload the mechanical PDF, review the takeoff, and line it up against each sub's scope. Your first takeoff is free and needs no card, and the sample file shows the exact Excel layout before you upload anything.
Run your first takeoff free
Upload a mechanical PDF and get a reviewable ductwork, fittings, and equipment takeoff you can export to Excel. No credit card to try your first drawing.
Built by a practicing P.Eng and principal of an Ontario mechanical contracting firm, for the estimators at that firm.
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Frequently asked questions
Can a general contractor use DuctIQ without an HVAC estimator?
Yes. DuctIQ does the measuring from the mechanical PDF and returns footage by system and size, fittings and equipment as line items. You do not need to trace duct yourself; you review the flagged lines and use the totals to compare bids.
Will DuctIQ tell me which mechanical bid is right?
No. It gives you independent duct quantities from the drawings. Comparing those with each sub's scope shows where the bids differ, so you can ask specific questions. Pricing and scope decisions stay with you and the subs.
Does it cover piping and plumbing too?
No. DuctIQ covers HVAC ductwork, fittings, air devices and equipment from the schedules. Piping and plumbing are outside its scope.
What drawings do I need?
The mechanical PDF set the subs bid from, with readable plan scales and duct size labels. Lines it cannot read with confidence are flagged with the reason instead of being filled in.
Can I share the takeoff with my subs?
The takeoff exports to standard Excel and CSV, so you can send the relevant lines to a sub when you ask about their scope.
How much does it cost to try?
Your first takeoff is free with no card required. Paid plans are listed on the pricing page if you want to keep using it.