Quantity Takeoff Methods and Units of Measure

What Is a Quantity Takeoff?

A quantity takeoff (QTO) is the process of reading a set of construction drawings and specifications to measure and count every item of work that must be installed or built. Estimators use these quantities to price labor, material, and equipment. A takeoff that is wrong — even by a small margin — can cause a contractor to overbid and lose work, or underbid and lose money. Accuracy is the single most important habit you will build in this course.

Quantities are organized by the CSI MasterFormat system, which divides all construction work into numbered divisions. In this lab you will work with four of them:

• Division 03 – Concrete
• Division 04 – Masonry
• Division 06 – Wood and Plastics (Framing)
• Division 09 – Finishes (Drywall)

The Four Takeoff Methods

1. Linear Measure

Linear measure counts length along one dimension, recorded in linear feet (LF) or lineal feet. Use it for items that run along a line: baseboards, pipes, beams, top plates, and bottom plates. Read the dimension from the drawing, account for corners and overlaps, and total the run.

2. Area Measure

Area measure multiplies two dimensions (length × width) and records the result in square feet (SF). Use it for floors, walls, ceilings, roofing, and sheathing. Always state which face you are measuring — gross area before openings are deducted, or net area after deductions. Industry practice varies by material: drywall is typically taken off net (openings deducted if they exceed a threshold set in your specifications), while roofing is taken off gross.

3. Volume Measure

Volume measure multiplies three dimensions (length × width × depth) and records the result in cubic yards (CY) for concrete and earthwork, or cubic feet (CF) for smaller quantities. Concrete is almost always ordered and priced by the cubic yard; one cubic yard equals 27 cubic feet. When a footing dimension is given in inches, convert to feet before calculating.

4. Count

Some items are enumerated individually. Masonry units (concrete masonry units, or CMU) are counted by the piece or reported as the number required per area. Doors, windows, light fixtures, and similar items are also counted. Record counts as EA (each) on your takeoff sheet.

Reading Drawings Safely in the Lab

The lab uses full-size printed drawing sets as well as Bluebeam Revu on screen. Keep your work area organized: a cluttered desk causes measurement errors. When using a physical architect's scale, confirm the scale printed on each sheet before you read any dimension — drawings are sometimes reproduced at a reduced size, which makes the printed scale bar the only reliable reference. Never scale a dimension when a written dimension is provided; always use the written number.

When you move between the computer and the light table or plotter area, follow the posted housekeeping rules: keep aisles clear, report any damaged equipment to the instructor immediately, and never attempt repairs yourself. Cuts from drawing-set paper edges are a common minor injury — handle large sheets carefully and use a straightedge when folding.

Standard Units by Trade Division

| Division | Typical Unit(s) |

|---|---|

| 03 – Concrete | CY (volume), SF (formwork) |

| 04 – Masonry | SF (wall area), EA (block count) |

| 06 – Wood Framing | LF (plates, headers), BF (board feet for lumber pricing) |

| 09 – Drywall | SF (board area), EA (panels) |

Board feet (BF) is a lumber-specific volume unit: 1 BF = 1 foot long × 1 foot wide × 1 inch thick. The formula is: BF = (thickness in inches × width in inches × length in feet) ÷ 12.

Setting Up Your Takeoff Sheet

A properly formatted takeoff sheet includes: project name, sheet/drawing reference, date, your name, CSI division, item description, quantity calculation (shown, not just the result), unit, and a notes column for assumptions. Never enter a raw number without showing where it came from. During peer review your partner must be able to trace every quantity back to a drawing sheet and a dimension.

Waste and Coverage Factors

Raw takeoff quantities are theoretical. In practice, estimators add a waste factor to account for cuts, breakage, and field conditions. Common factors: masonry — 3–5% waste; drywall — 10–12% waste; framing lumber — 10–15% waste. Your instructor will specify which factors to apply in today's lab. Always label whether a quantity is net (theoretical) or gross (with waste included).

Checking Your Work

After completing a division, perform a quick reasonableness check: Does the concrete volume seem right for the size of the building? Does the block count roughly match the wall area divided by the face area of one block? Cross-checking by a second method catches most errors before peer review. The peer-review checklist you will use today asks for arithmetic verification, unit consistency, and completeness against the project scope — the same review a senior estimator performs before a bid is submitted.