Taking off quantities from a PDF, and what they are for

Why you take off at all

A quantity takeoff is the list of what the building is made of, measured: how many linear feet of partition, how many square feet of flooring, how many doors of each type, how many cubic yards of concrete. It is not the estimate. It is what the estimate stands on.

And it gets reused far more often than people expect. The same quantity, if it was measured well, feeds at least six different jobs after the bid:

• Pricing. Quantity times unit cost. The obvious one, and the only one most people think about when they measure.
• Buying. Purchase orders are placed in pieces, boxes, sheets and truckloads. The buyer starts from your quantity and adds waste and pack sizes on top.
• Scheduling. Duration is quantity divided by production rate. A partition quantity that is 20% low produces a drywall activity that is 20% short.
• Buying out subs. When three drywall subs send prices, the GC's own quantity is the only way to tell which one left something out.
• Billing and progress. A schedule of values broken down by floor and by trade lets you bill what is actually installed, and lets the owner's rep check it.
• Changes. When a new drawing set arrives, the change order is the difference between the old quantity and the new one. If you cannot find the old one, you cannot price the change.

Check the scale before you measure anything

A PDF has no idea what scale it is. It is an image with a page size, and everything you measure on it is multiplied by a scale that you declare. Get that one number wrong and every quantity on the sheet is wrong by the same factor — neatly, consistently, with no error message.

The classic case: a 22 × 34 in set printed half-size on 11 × 17 paper and scanned back to PDF. The title block still says 1/4" = 1'-0", but the drawing is now at 1/8". Measure it at 1/4" and every length comes out at half and every area at a quarter. Nobody notices because the numbers look reasonable: a 1,200 SF apartment reads as 300 SF, and 300 SF is a perfectly believable room.

The subtle case is worse: a PDF exported with «fit to page» at 95%. Lengths are off by 5%, areas by roughly 10% (0.95 × 0.95 ≈ 0.90), volumes by roughly 14%. Nothing looks wrong. The error is only big enough to eat your margin.

How to check it, every sheet

Two more habits. A graphic scale bar survives resizing, because it shrinks along with the drawing; a written scale does not. And a view marked NTS (not to scale) is not measured, full stop — you take its dimensions from the numbers written on it, or from another view. For more on how scales and sheet sizes are chosen, see the drawing set guide.

Measurement rules: decide them before you start

Two estimators can measure the same wall correctly and get different numbers, because they followed different rules. That is not a problem. Not writing the rules down is. Before you measure, settle these questions and put the answers on the first page of the takeoff.

Net or gross

Net is what is actually built: the wall minus its openings, the floor minus the shaft. Gross ignores the holes. The general principle that keeps a takeoff clean is to measure net, as drawn, and handle everything else in pricing: waste, laps, cutting, overbreak, swell. The drawing describes the building; allowances describe how you will build it, and they belong in a different column.

The exception is the contract. When a bid form or a spec section's «measurement and payment» clause says how an item is measured — common on public and unit-price work — that rule wins over your habit, and you note that you followed it.

Openings

There is no universal rule for openings. Some companies deduct every opening; some deduct only openings above a size threshold they set themselves; some deduct none and price the extra labor at jambs and heads separately. Any of those is defensible if it is written down and applied the same way on every sheet. What is not defensible is deducting doors on floor 2 and forgetting on floor 3.

Whatever the rule, remember that openings affect more than one item. A door deducted from the drywall also interrupts the baseboard, adds a frame, hardware and possibly a header, and appears in the door schedule. Count it once as a door; account for its effect on each neighboring item.

Centerline or face

Walls taken off by length by type are usually measured along the centerline. At an L corner, the outside face is longer and the inside face shorter; the centerline sits between the two and adds up correctly around the building. Finishes — paint, wall tile, the face of the board — are measured at the face where they go, which usually means the inside perimeter of each room.

At intersections, decide once where a wall stops: at the face of the wall it runs into, or at its centerline. For partitions the difference is small. For concrete walls and footings, measuring both members through the intersection counts the same cubic yards twice.

Heights

The plan gives you lengths. Heights come from somewhere else: wall types, building and wall sections, the reflected ceiling plan. A partition may stop 6 in above the ceiling or run to the underside of the deck; the plan looks identical either way. Read the wall type legend before measuring a single wall, note where each height came from, and watch for rooms with a different ceiling height — bathrooms and corridors with soffits are the usual ones.

These are common practices, not a standard. Your company, the bid form or the specs may say otherwise — and when they do, they govern.

Four kinds of quantity, and their units

Almost everything on a drawing set is measured in one of four ways. Choosing the right one is not a formality: the unit you measure in has to be the unit you will price in. A flooring price per square yard applied to a quantity in square feet is off by a factor of nine, and it happens more than anyone admits.

Some items take a fifth kind — weight, such as reinforcing steel in tons or pounds — usually derived from lengths and bar sizes rather than measured directly.

A useful habit: for walls, keep both the linear and the area quantity. Length drives the layout, track and framing crews; area drives the board, finish and paint. Measuring once and deriving the other from the height keeps them consistent.

Organize it so it can be priced

A takeoff that is one long list of numbers is finished for the person who made it and useless for everyone else. It needs two axes: what it is and where it is.

What: by trade and division

In the US, the usual backbone is CSI MasterFormat, which organizes work by divisions — 03 Concrete, 05 Metals, 06 Wood, Plastics, and Composites, 07 Thermal and Moisture Protection, 08 Openings, 09 Finishes, 22 Plumbing, 23 HVAC, 26 Electrical, 31 Earthwork, and so on. Some owners and early-phase estimates use UniFormat instead, which groups by building element (substructure, shell, interiors, services). Use the one your estimate and your specs use, so each takeoff item lands in exactly one line of the budget and one subcontract.

Where: by location

Measure by floor, and by zone when a floor is large. The total does not change, but everything downstream does: the schedule is built by location, subs are released by location, progress is billed by location, and a revision that only touches Level 3 only reopens Level 3.

Illustrative numbers. The section numbers follow MasterFormat; use the ones your own specs use.

Naming

Name items with the words of the drawings. If the wall type legend calls it P1, the takeoff calls it P1, not «interior wall» — so anyone can find it on the sheet. A pattern that works: division · what · type tag · spec detail, for example «09 21 16 · Partition P1 · 3-5/8" mtl stud, 1 layer 5/8" GWB each side». Location goes in its own column, not in the name, so you can total by floor without editing text.

Measured quantity and waste: keep them apart

The takeoff says what the drawing shows. Waste says what you expect to lose cutting, fitting, breaking and rounding up to full pieces. They are different facts, with different owners, and they go in different columns.

If you bury 10% waste inside the measured quantity, three things break. The next estimator adds waste again when pricing, and now it is 21%. The scheduler divides an inflated quantity by a production rate and gets an inflated duration. And when the owner's rep checks your progress billing against the drawings, your quantities do not match theirs, and you spend a meeting explaining why.

What waste factor to use depends on the material, the layout, the crew and the supplier's pack sizes; your own job history is the best source. Whatever you use, write it next to the item, and apply it when you convert quantities to purchases — where rounding up to full boxes, sheets or lengths also happens.

Traceability: every number has an address

Every quantity should be able to answer, on its own, four questions: which sheet, which revision, what date, and at what scale. Add who measured it and you have everything needed to defend it, check it, or update it.

• Sheet and revision. «A-102, Rev 3» — not «the second floor plan». There may be three second floor plans by the end of the job.
• Date of the set. The issue date printed on the sheet, not the day you measured.
• Markups on the drawing. Color each measured element by item. Anything left uncolored has not been measured, and you can see it from across the room.
• Assumptions. «Height per wall type P1, A-601», «closets without baseboard», «doors deducted per company rule». One line each.

This is not bureaucracy. It is what lets you answer «where did this number come from?» in ten seconds instead of re-measuring the floor.

A worked example: one floor, four apartments

Here is the method on a small, simple case. All the numbers below are invented for the example: they are plausible, they add up, and they are not industry statistics or benchmarks.

The measured quantities

Company rules for this example: walls at centerline; heights from the wall types; all door openings deducted from the board; closets without baseboard; baseboard stops at kitchen cabinets.

Where the deductions come from

• Openings in P1: 20 type B doors at 21 SF (3 × 7 ft) = 420 SF, plus 8 type C doors at 28 SF (4 × 7 ft) = 224 SF. Total 644 SF per face, 1,288 SF for both faces. The entry doors sit in the corridor wall, which is a different type and is not in this table.
• Baseboard: type B doors interrupt it on both sides, 40 × 3 LF = 120 LF; closet doors only on the room side, 8 × 4 LF = 32 LF; entry doors, 4 × 3 LF = 12 LF; kitchen cabinets, 4 × 14 LF = 56 LF. Total 220 LF.

From measured to purchased

Only now does waste appear — in its own column, with the percentage written down. The percentages here are part of the example, not a recommendation.

The check against the area schedule

LVP plus tile is 3,720 + 520 = 4,240 SF. The area schedule says 4,600 SF of net unit area. The 360 SF difference is not automatically an error — but it has to be explainable. The P1 partitions take up about 620 LF × 4-7/8" ≈ 250 SF of floor; the P2 demising walls about 150 LF × 7-1/4" ≈ 90 SF. That leaves roughly 20 SF, which matches the plumbing chases shown on the plan. Explained, so it goes in the notes and the takeoff moves on. If the gap had been 1,000 SF, a room would be missing.

Before trusting that comparison, read how the schedule measures area: to the inside face of walls, to the centerline of demising walls, or some other convention. Two correct numbers measured by different rules will never match.

Check your own takeoff

Nobody catches their own mistakes by re-reading their own numbers. The checks that work are the ones that look at the same thing from a different direction.

• Ratios against your own history. Linear feet of partition per square foot of floor, doors per apartment, fixtures per bathroom. Compare them with similar past jobs of yours. A ratio that is off does not prove an error; it tells you where to look first.
• A second source for every count. Doors counted on the plan against the door schedule; fixtures on the plan against the plumbing fixture schedule. When they disagree, you have found either your error or the designer's — and both are worth finding before the bid.
• Areas against the area schedule, as in the example: the difference must be small and explainable.
• Typical floors against each other. If Levels 2, 3 and 4 are the same plan, their quantities must be the same. If they differ, either the plans differ or the takeoff does.
• A second pass on the big items. A few items usually carry most of the cost. Have someone else re-measure those, or re-measure them yourself with a different method.
• The uncolored check. Page through every sheet looking for anything without a markup. Items shown only in details, enlarged plans or general notes are the ones that get missed.

When a new drawing set arrives

Revisions are the rule, not the exception. The two wrong reactions are starting over from scratch and carrying on as if nothing happened. The right one is in between:

• Log the new set. Sheet, revision and issue date, before touching a quantity.
• Find what changed. Read the revision clouds and deltas, but do not trust them blindly: overlaying the old and new sheet is the only way to see changes nobody clouded.
• Re-measure only what is affected, and by location — which is why you measured by floor and zone in the first place.
• Keep the old quantity next to the new one. The difference is the change order, or the reason the budget moved. Overwriting the old number throws away the evidence.
• Update the references on every touched item, and mark superseded sheets so nobody measures off them again.

For how revisions are issued and tracked on the design side, see the revisions guide.

The most common mistakes

• Measuring at the wrong scale. Half-size prints, «fit to page» exports, and details on the same sheet as the plan at a different scale.
• Mixing waste into the measured quantity, then adding it again in pricing.
• Counting the same thing twice. The same wall on the overall plan and on the enlarged plan; the same concrete at a wall–footing intersection.
• Missing what is not on the plan. Heights from sections, items in general notes («all wet walls to receive cement board»), work shown only in details or in the specs.
• Measuring in one unit and pricing in another. SF against a price per SY, CF against a price per CY.
• Multiplying typical floors blindly, including the one that is mirrored or has a different unit mix.
• Including what is not in the contract. Items marked NIC or «by owner» are measured, if at all, in a separate list.
• Numbers with no address. A quantity without sheet, revision and date cannot be checked, updated or defended.

Frequently asked questions