Using the plan-reading drills to practice takeoffs

What the drills are

• Plan-reading drill 1: a floor plan with a door schedule, an exterior wall section and a site plan.
• Plan-reading drill 2: a foundation plan with a footing schedule, a roof framing plan with a member schedule, and a reflected ceiling and mechanical plan. Drill 2 also hides a few coordination conflicts on purpose, the kind you would send an RFI about.

Every number on the sheets is invented. They are generic practice drawings, not copies of the test-center packet, which we have not seen. Each answer shows its arithmetic worked one way and checked another. After a set, the drill lists the skills where you lost points, most missed first. A new set reshuffles the questions.

Read every sheet in the same order

Before you answer anything, spend a minute on the sheet the way an estimator would:

1. Title and scale. Note the scale of each view. A detail can be at a different scale from the plan.
2. Notes and abbreviations. General notes often say how dimensions are taken, such as to wall centerlines or to face of stud.
3. Overall dimensions, then the strings. Add each dimension string and check it against the overall. A string that does not close is either a drafting error or a sign you misread a figure.
4. Schedules. Find the door, footing or fixture schedule and the marks that tie it to the plan.
5. Then the questions.

Written dimensions beat scaling. The drill's own advice is that a scale note holds only on a full-size print, so a screen or a reduced copy cannot be measured. Use the dimensions given.

A takeoff, worked the way the drills work

This example is ours, not from either drill, and every number is invented. A building is 48'-0" by 32'-0" to the outside of the slab. The north dimension string reads 14'-6", 18'-0" and 15'-6". The slab is 4 in thick, and a continuous footing 2 ft wide and 1 ft deep runs under the exterior walls on their centerline.

Close the string. 14.5 + 18 + 15.5 = 48.0 ft, matching the overall. Good.

Scale check. At 1/8 in = 1 ft, 6 in on a full-size print is 6 x 8 = 48 ft. Check: 48 / 8 = 6.

Slab.

• Area: 48 x 32 = 1,536 sq ft
• Volume: 1,536 x 4/12 = 512 cu ft, and 512 / 27 = 18.96 cu yd
• Check: 1,536 / 3 = 512, and 18.96 x 27 = 511.9, within rounding
• With 5% waste: 18.96 x 1.05 = 19.91, so order 20 cu yd

Footing. Take the perimeter on the footing's centerline, so the corners are not counted twice. If the walls' centerline sits 0.5 ft in from the slab edge, the centerline rectangle is 47 by 31 ft.

• Centerline perimeter: 2 x (47 + 31) = 156 ft
• Volume: 156 x 2 x 1 = 312 cu ft, and 312 / 27 = 11.56 cu yd
• Check: 312 / 27 = 11.555..., and 11.56 x 27 = 312.1

Using the outside perimeter instead, 2 x (48 + 32) = 160 ft, would overstate the footing by 4 ft of length, 8 cu ft. Small here, but it is exactly the kind of slip a wrong answer option is built from.

A grade. Existing grade at one corner is 97.40 and the pad's finished grade is 98.50. That corner needs 1.10 ft of fill. Check: 97.40 + 1.10 = 98.50. If the numbers were the other way round, it would be cut. Write "FG minus EG" every time and the sign tells you which.

The free concrete yardage calculator runs slab and footing volumes with waste step by step, so you can check your hand work.

Turn misses into a plan

When a set ends, read the list of skills you missed and match the fix:

• Scale and dimensions: you misread a string or scaled when a dimension was given. Close every string before you answer.
• Quantity takeoff: a unit slip, usually square feet against cubic yards, or a perimeter that double counts corners. Write the units on every line.
• Schedules and keynotes: you read the plan without the schedule. Find the mark, then the row.
• Layers in section: read the wall section from outside to inside, every time.
• Grades and earthwork: a sign flipped. Finished minus existing, positive is fill.

Run a new set the next day. When a skill stops showing up, time yourself: about 2.6 minutes a question is the exam's average pace (330 minutes over 125 questions, counting the 10 unscored ones), and drawing questions should come in under it. The blueprint packet guide covers what the bulletin does and does not say about the packet.

Where this sits for the exam

The bulletin names the packet but does not tie it to a subject area. Takeoffs and earthwork show up naturally in Site Construction, Concrete and estimating questions, by our reading.

Next step

Take the free check to see your weakest subject area. It needs no signup and explains every answer. For a lesson on each area, more practice questions and timed practice exams, see the plans.

Sources

• PSI Candidate Information Bulletin 1458, the diagram and blueprint packet and the content outline, updated 7 Jul 2026. Retrieved 5 Nov 2026.
• All dimensions are invented and every calculation was worked twice.

FAQ

Are the drill sheets the same as the NASCLA blueprint packet?

No. They are our own practice drawings. The bulletin says a packet is handed out at the test center but does not describe it.

Should I scale dimensions off the drawing?

Use written dimensions when they are given. A scale note holds only on a full-size print.

Why measure footings on the centerline?

Taking the perimeter on the centerline counts each corner once. The outside perimeter overstates the length.