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Structural Steel Takeoff Example: Step by Step

SteelFlo Team9 min read

Structural Steel Takeoff Example: Step by Step

Here's a complete structural steel takeoff example, start to finish: a 60' x 80' single-story retail shell, 104 pieces of steel, 47,237 lbs (23.6 tons) total. We walk the drawing set page by page, count every column, girder, beam, brace, and lintel, calculate weights from catalog pounds-per-foot values, and roll it all up into a finished bill of materials you can copy for your own jobs.

If you've read what a steel takeoff is and want to see one actually done with real numbers, this is that walkthrough.

The Job: A Small Commercial Building

The example project is a single-story retail shell — the kind of job a 5-to-20-person fab shop bids every week:

| Parameter | Value | |---|---| | Footprint | 60' x 80' (4,800 sq ft) | | Grid | Lines 1–5 @ 20'-0" (80' direction), lines A–C @ 30'-0" (60' direction) | | Eave height | 20'-0" | | Roof system | Steel beams and girders, metal deck (deck by others) | | Drawing set | S0.1 general notes, S1.1 foundation plan, S2.1 roof framing plan, S3.1 sections, S4.1 details | | Steel scope | Columns, roof framing, wall bracing, loose lintels, RTU frames, base plates |

Five structural sheets. Joists, deck, and stairs are excluded from scope on this one, which keeps the example clean.

Step 1: Page-by-Page Plan Review and Scope Notes

Before counting anything, walk the whole set once and write scope notes. On this job that pass takes 20–30 minutes and produces notes like:

  • S0.1 (general notes): Material grades — A992 for wide flange, A500 Gr. C for HSS, A36 for plates, angles, and channels. Standard AISC framed connections unless noted. This is where camber callouts and paint/galvanizing specs hide; none on this job.
  • S1.1 (foundation plan): 15 column base plates shown with anchor bolt layouts. Anchor bolts by others (confirm in the notes — this is a classic scope fight).
  • S2.1 (roof framing plan): The money sheet. All beams and girders tagged with sizes. Two RTU openings flagged with channel frames.
  • S3.1 (sections): Confirms column heights (19'-6" cut length, we'll carry 20'-0") and shows the braced bays — X-bracing in two wall bays each direction.
  • S4.1 (details): Shear tab and clip angle connection details, base plate detail (PL 3/4" x 12" x 12"), loose lintel schedule for six masonry openings.

If any of this feels unfamiliar, our guide on how to read structural drawings covers sheet numbering, grid systems, and where member callouts live.

Step 2: Counting Beams and Columns from Plans and Schedules

Now the actual count. The rule that keeps you out of trouble: count marks on the plan, one tick per piece, and reconcile against any schedule. Never trust "typical" notes without tracing where they apply.

On S2.1:

  • Columns: One at every grid intersection — 5 lines x 3 lines = 15 columns, all HSS8X8X1/4. The section on S3.1 gives the length; we carry 20'-0" each.
  • Girders: W21X44 spanning the 30' direction along each numbered grid line. Two spans per line x 5 lines = 10 girders at 30'-0".
  • Filler beams: W12X26 spanning 20' between girders, spaced 7'-6" on center. Nine beam lines across the building x 4 spans = 36 beams at 20'-0".

The single most common manual takeoff error happens right here: a filler beam line gets counted on one bay and assumed "typical" for the rest, and the assumption is wrong by one line. Miss one beam line on this job and you're short 4 pieces and 2,080 lbs. Tick every mark.

Running count after Step 2: 61 pieces of main steel.

Step 3: Connections, Base Plates, and Misc Steel

Main framing is the easy 80%. The last 20% is where estimates leak money:

  • Wall bracing: S3.1 shows X-braced bays — two braced bays per wall direction, two HSS6X6X1/4 braces per bay = 8 braces. Work-point to work-point they scale to roughly 23'-6"; we carry 24'-0" cut length each.
  • Loose lintels: The S4.1 lintel schedule calls L4X4X1/4 pairs over six masonry openings = 12 angles at 6'-0".
  • RTU frames: Two rooftop units, each framed with four C8X11.5 channels = 8 channels at 8'-0".
  • Base plates: 15 columns x one PL 3/4" x 12" x 12" each = 15 plates. Plate weight: 0.75/12 ft thick x 1 sq ft x 490 lbs/cu ft = 30.6 lbs each.
  • Connection material: Shear tabs, clip angles, and stiffeners per the S4.1 details. For a simple job like this, most shops carry a percentage allowance instead of counting every tab — we use 5% of main steel weight. On heavier moment-frame work you'd count connection material piece by piece.

Final piece count: 104 pieces (15 + 10 + 36 + 8 + 12 + 8 + 15).

Step 4: Lengths, Weights, and the Tonnage Roll-Up

Every wide flange, channel, and angle designation encodes its weight per foot (a W21X44 weighs 44 lbs/ft; a C8X11.5 weighs 11.5 lbs/ft). HSS is the exception — the name gives dimensions, so you pull pounds-per-foot from the AISC tables: HSS8X8X1/4 runs 25.82 lbs/ft and HSS6X6X1/4 runs 19.02 lbs/ft.

The math is quantity x length x weight-per-foot, line by line:

| Item | Section | Qty | Length | Total LF | Lbs/ft | Weight (lbs) | |---|---|---|---|---|---|---| | Columns | HSS8X8X1/4 | 15 | 20'-0" | 300 | 25.82 | 7,746 | | Roof girders | W21X44 | 10 | 30'-0" | 300 | 44.0 | 13,200 | | Roof beams | W12X26 | 36 | 20'-0" | 720 | 26.0 | 18,720 | | Wall braces | HSS6X6X1/4 | 8 | 24'-0" | 192 | 19.02 | 3,652 | | Loose lintels | L4X4X1/4 | 12 | 6'-0" | 72 | 6.6 | 475 | | RTU frames | C8X11.5 | 8 | 8'-0" | 64 | 11.5 | 736 | | Base plates | PL 3/4x12x12 | 15 | — | — | 30.6 ea | 459 | | Subtotal | | 104 | | 1,648 | | 44,988 | | Connection allowance (5%) | | | | | | 2,249 | | Total | | | | | | 47,237 |

Total: 47,237 lbs = 23.6 tons.

Now the sanity check, and this step catches more busted takeoffs than any other: divide total weight by floor area. 47,237 lbs / 4,800 sq ft = 9.8 lbs per square foot. Single-story commercial steel typically lands between 5 and 10 psf. We're at the top of that range — reasonable for a 20' eave with full beam framing and no joists. If this number had come out at 3 psf or 18 psf, something in the count is wrong and you go find it before the bid goes out.

For pricing, each line becomes weight x material cost per pound plus fabrication labor — you can run these totals through our free steel weight calculator to check the per-line math.

Step 5: The Finished BOM

The takeoff becomes a bill of materials by grouping identical pieces, assigning grades, and adding remarks the shop and purchasing actually need:

| Mark | Qty | Section | Grade | Length | Weight ea (lbs) | Total (lbs) | Remarks | |---|---|---|---|---|---|---|---| | C1 | 15 | HSS8X8X1/4 | A500 Gr. C | 20'-0" | 516 | 7,746 | w/ cap PL, BP-1 | | G1 | 10 | W21X44 | A992 | 30'-0" | 1,320 | 13,200 | Shear tabs both ends | | B1 | 36 | W12X26 | A992 | 20'-0" | 520 | 18,720 | Clip angles both ends | | BR1 | 8 | HSS6X6X1/4 | A500 Gr. C | 24'-0" | 457 | 3,652 | Slotted, gusset conn. | | L1 | 12 | L4X4X1/4 | A36 | 6'-0" | 40 | 475 | Loose, galv. per arch | | F1 | 8 | C8X11.5 | A36 | 8'-0" | 92 | 736 | RTU frames, field weld | | BP1 | 15 | PL 3/4x12x12 | A36 | — | 31 | 459 | 4 anchor bolt holes |

Want this exact format to reuse? Grab the free steel takeoff template for Excel — it's the same column layout with the weight formulas built in. And for what belongs in each column and why (grades, mark numbers, remarks), see how to create a bill of materials.

How Long It Took: Manual vs. AI + Human Verification

This is a small, clean, five-sheet job, and the honest manual numbers still add up:

| Task | Manual time | |---|---| | Plan review and scope notes | 30 min | | Counting main framing | 60 min | | Bracing, lintels, misc, plates | 45 min | | Weight calcs and roll-up | 30 min | | BOM formatting and double-check | 45 min | | Total | ~3.5 hours |

Scale that to a real bid set — 30 sheets, revisions mid-bid, three jobs due Friday — and the takeoff becomes the bottleneck of your whole estimating week. That's the problem AI-assisted takeoff tools attack: software like SteelFlo reads the PDF set, finds and boxes every member callout across all pages (it recognizes 4,500+ steel sections across 6 international standards), and hands you the count for review. You verify the flagged items instead of ticking every mark from scratch — that AI-plus-human-verification workflow is what produces 95-99% accuracy, and it turns the 2-plus hours of counting above into minutes of review. The plan-reading judgment in Steps 1 and 3 — scope, exclusions, what "by others" really means — stays with you. That's the part worth your time anyway.

Want to try it on the next drawing set that hits your inbox? Run this same workflow in SteelFlo — upload the PDF, review the detected members, export the finished BOM. Your first 3 takeoffs are free.

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