CSLB General Building (B)Planning and EstimatingEasy
A floor plan is drawn at a scale of 1/4 inch = 1 foot. A contractor measures an interior wall on the drawing and finds it to be 3 inches long. What is the actual length of the wall?
- A9 feet
- B12 feet
- C16 feet
- D3 feet
Show answer & explanationAnswer & explanation
Correct answer: B. 12 feet
At 1/4 inch = 1 foot, each inch on the drawing represents 4 feet. Therefore 3 inches x 4 feet/inch = 12 feet of actual wall length.
Why the other options are wrong
- A. This would result from multiplying by 3 instead of 4.
- C. This overestimates the conversion factor.
- D. This ignores the scale conversion entirely.
Architectural Scale Conversion
A method of converting measured distances on a scaled drawing into actual field dimensions using the stated drawing scale.
- 1/4 inch = 1 foot means each inch equals 4 feet
- Always identify the scale noted on the drawing title block first
- Use a scale ruler for accuracy instead of a standard ruler
Memory trick: One inch on paper, four feet in the field.