How to do a construction takeoff, step by step (with a worked example)

What you need before you start

• The complete plan set and every addendum. Take off from the latest revision. A takeoff done on superseded sheets is the most expensive mistake on this list.
• The specifications. They tell you materials, thicknesses and what counts as your scope. The plan shows where; the specs say what.
• Your scope of work. The bid form, the invitation to bid or the subcontract scope sheet. Know what you are pricing before you measure it.
• A place to record quantities. A takeoff sheet in Excel works (we publish a free construction takeoff template with Key, Item and Unit columns that line up with TRACEBUILD's export; its Qty column takes the export's Total), or a takeoff tool that measures on the PDF directly.

Step 1: Set the scale, then prove it

Every length and area you measure is only as good as the scale behind it, so set it first and then check it against a dimension printed on the sheet. If a known dimension does not measure right, stop and fix the scale before you take anything off.

Our sheet, drawing A2-2, has the scale note 1:50 under its title. It is a metric drawing, as many federal projects are, so dimensions are in millimetres. When we ran our first detection, TRACEBUILD read that note, pre-selected 1:50, and warned that the PDF is not a standard sheet size, so its printed scale may not match the file.

So we checked it. Between grid lines 2 and 1 the drawing dimensions the bay at 7280 mm. We measured that bay with the Length tool, snapping to the dimension ticks, and got 7.27 m, 10 mm short, or 0.14%. That is a pass: a scale error would show up as a much bigger miss, such as double or half the length.

If a sheet has no readable scale note, pick its scale from the list of standard architectural, engineering and metric scales, or calibrate from a long known dimension. Then run the same check. The drawing scales guide has every standard scale with its ratio and feet per inch, plus what to do with mixed scales and NTS details.

Watch for: a sheet with more than one scale (enlarged plans and details often sit beside the main plan at a different scale), details marked NTS (not to scale, never measure them), and sets printed at half size, where every scale note is wrong by a factor of two.

Step 2: Measure areas

Measure each area by type and by room, because that is how you will price it: floor finish by room, wall area by paint system, roof by plane. Trace to the inside face of the walls unless your method says otherwise, and keep every type on its own line so the totals stay separable.

On our sheet we ran Detect Spaces on the whole plan. It proposed 34 rooms and named them from the drawing's own room labels. Proposed rooms are not counted in the takeoff totals until you accept them, and the review panel marks each one with how confident it is. On this sheet many were marked "little ink here, check the placement", and two outlines were invalid.

Then we reviewed the five TRICARE offices on the east side, the part of the plan we were taking off, against the walls on the sheet:

• Four offices matched the walls. 1A03, 1A04, 1A06 and 1A07 followed the inside faces of their walls, so we accepted them.
• One outline was invalid. The panel flagged office 1A05 as "invalid outline (self-intersecting)", so we rejected it and drew the room by hand with the Area tool, corner to corner along the inside faces of the walls: 8.61 m².

The arithmetic, for when you do it by hand: a rectangular room is length times width, and an L-shaped room is two rectangles added together. The rectangle we traced for office 1A05 is about 2.98 m by 2.87 m, which is 8.55 m² by hand; the tool reports 8.61 m² because its corners snapped to the wall lines, a difference under 1%. In feet: 1 m² is 10.764 SF, so 8.61 m² is 92.7 SF.

Step 3: Measure lengths

Lengths cover everything priced by the linear foot: walls, base, pipe, conduit, duct, curb, footings and trim. Measure each run by type and size, snap to the linework so the line sits on the drawing, and check the class of anything a tool traced for you before it goes into a price.

We ran Trace Walls in a box drawn around the office suite. It proposed 11 wall segments, and we accepted 10 of them, 45.36 m in total (148.8 LF), sorted into classes: 8 segments of "Interior bearing wall" (25.14 m), 1 "Partition" (2.10 m) and 1 "Exterior wall" (18.13 m). The eleventh, a 3.78 m interior segment, was never accepted. Traced walls are proposals until you accept them, so it is listed on the Markups sheet of the export but left out of every total on the Takeoff sheet.

That last one is wrong for our purposes. The 18.13 m run is the long wall on the west side of the suite, between the offices and the storage and conveyor spaces next to them. It is an interior wall. It also runs well past the suite at both ends, because a traced wall follows the wall to its end, not to your box. If you price walls by type or by room, split and reclass a run like this before pricing. Traced walls also read "set height" until you give them a wall height, which is how they turn into wall area for paint or drywall.

For base, the Perimeter tool closes a loop around a room. On the finish plan for the same block, the loop around office 1A06 measures 12.47 m; take out a 0.91 m door opening (the width Detect Spaces reported for the office doors on that sheet) and you have 11.56 m (37.9 LF) of base for that room.

Step 4: Count items

Counts cover everything priced each: doors, fixtures, devices, diffusers and equipment. Count one symbol type at a time across the sheet, label each count by the drawing's own mark, and check the total against the schedule. Counting does not depend on the scale, so you can count before the scale is set.

We counted the five office doors with the Count tool, one click per door, under the item name "Doors (office)". Each click drops a numbered marker, so the count on the sheet and the count in the takeoff can never disagree. Five doors, five markers.

Two habits keep counts right:

• Work legend by legend. Count every water closet, then every lavatory, not room by room. You miss fewer symbols and you never count one twice.
• Reconcile with the schedule. If the fixture or door schedule says 12 and you counted 11, find the twelfth or write an RFI. Our plumbing takeoff example counts fixtures by mark against the fixture schedule on the same set.

For repeated symbols, TRACEBUILD Lite has Visual Search: box one symbol and it searches for matching symbols so you can review the hits and add them as counts. AI symbol detection is part of TRACEBUILD Pro, which is coming soon.

Step 5: Deductions and waste

Measured quantities are net; what you order is net plus waste. Deduct openings where your method calls for it, such as doors and windows from wall area, then apply a waste factor per material for cutting, pattern matching and breakage. Record the waste in its own column so anyone can see how you got from net to order.

Waste depends on the material, the layout and the crew, so treat the numbers below as a starting point and replace them with your own history and your supplier's guidance.

Typical planning ranges from common estimating practice, not TRACEBUILD data. Confirm with your supplier and your own job history.

Applied to our example: the five offices total 434.1 SF of floor. At 5% waste for resilient tile, that is 434.1 × 1.05 = 455.8 SF to order, before rounding up to whole cartons.

Step 6: Organize by trade and export

Name every item the way you price it and keep trades apart, by CSI division if your estimate is organized that way. Then export the quantities to Excel or CSV so they drop into your pricing sheet without retyping. Retyping quantities is where transposed digits get into bids.

TRACEBUILD's Excel export has two sheets. Markups lists every measurement with its page, type, space, item name, value and unit. Takeoff totals them three ways: by item, by space, and by layer and type. Each total row carries a key in column A that stays the same when you re-export after a revision, so a pricing sheet that looks up by key keeps working when the drawing changes.

Our export for this example: tracebuild-example-a2-2-office-suite.xlsx (26 KB). If you would rather start from a blank sheet, the construction takeoff template has a tab per trade with units and waste columns already set up. The export guide covers the columns in detail.

The worked example: results

Drawing A2-2, First Floor Plan Block 1A, public-domain USACE clinic set, scale 1:50. Quantities are exactly as TRACEBUILD reported them in metric; the feet column is our conversion (1 m² = 10.764 SF, 1 m = 3.281 ft).

Download: the exported workbook. The plan set is the demo set inside TRACEBUILD, so you can repeat the steps: open the demo set, go to sheet 3 and run them. Detected areas should match ours; anything drawn by hand will differ a little with where you click.

Material takeoff vs quantity takeoff

A quantity takeoff measures the work as drawn: 434.1 SF of office floor, 5 doors, 148.8 LF of wall. A material takeoff turns those quantities into what you buy: cartons of tile after waste, sheets of board by length, bags of adhesive by coverage, door frames and hardware sets by type. You need the quantity takeoff first; the material takeoff applies waste, packaging and coverage rates to it. Many estimators keep both on one sheet, quantity on the left and order quantity on the right.

Manual, digital or detection-assisted?

Manual takeoff with a scale ruler and highlighters still works, and it is the right way to learn. It is slow, and every number has to be typed again into the estimate. Digital takeoff on a PDF does the arithmetic for you, keeps a visual record of every measurement, and exports the totals. Detection-assisted takeoff proposes rooms, walls and runs for you to review.

Our example shows both what detection saves and why review is not optional. Detect Spaces outlined four of our five offices correctly in one pass, which saved four rooms of tracing, but the fifth office had an invalid outline (two on the whole sheet), and many of its 34 proposals were flagged for a placement check. Trace Walls found the walls but put one of ten in the wrong class. Review every detected item before it goes into a bid. For wall tracing, we publish a wall-detection benchmark you can download and rerun; it measures wall detection only, on labelled synthetic plans, and says so.

The 10 most common takeoff mistakes

1. Wrong scale. A half-size print or a detail at a different scale. Check a known dimension on every sheet.
2. Old sheets. Taking off before the last addendum. Log the revision of every sheet you measure.
3. Measuring NTS details. Anything marked not to scale gives you a number that means nothing.
4. Double counting at match lines. Rooms and runs that cross a match line get counted on both sheets.
5. Missing scope in notes and schedules. Keyed notes, finish schedules and general notes add work the plan view does not show.
6. Mixing units. Square feet and square yards, or millimetres and inches, in the same column.
7. Forgetting openings, or deducting them twice. Decide your deduction rule per trade and apply it the same way everywhere.
8. No waste, or waste applied twice. Keep waste in its own column so it is applied once and visible.
9. Trusting detection without review. As our example shows, one invalid outline or one misclassed wall is enough to skew a number.
10. Retyping quantities into the estimate. Export them instead, and check a few totals against the drawing.

Takeoff by trade

Each trade measures different things in different units. The trade guides go deeper, with a worked example where we have one.