How to read construction plans
Before you can take off a set of drawings, you have to find your way around it: which sheet is which, what scale it is, and what the symbols mean. Here is how a plan set is organized and how to read it for takeoff.
The parts of a plan set
- Cover sheet and drawing index, the map of the whole set and where to find each sheet.
- Discipline sheets by letter, A architectural, S structural, M mechanical, E electrical, P plumbing, C civil.
- Title block, the sheet name and number, the scale, the date, and revisions.
- Scale and dimension strings, how on-sheet distances relate to real feet.
- Schedules, tables of doors, fixtures, equipment, and finishes, often with quantities.
- Legend and symbols, what each mark on the drawing represents.
Read a set for takeoff, step by step
- Start with the cover and index. See how the set is organized and which sheets carry the work you are bidding.
- Find your discipline sheets. Jump to your trade by its letter prefix, then work through those sheets in order.
- Check the scale and title block. Confirm the scale before you measure anything, since it can change between sheets.
- Read the schedules and legend. Learn what each mark means and what quantities to expect, so your takeoff has something to check against.
- Take it off. Measure areas and lengths and count symbols, sheet by sheet, keeping each type on its own group.
Ready to take it off?
Once you can read the set, the next steps are setting the scale and measuring area and length. Then go to your trade for exactly what to measure and count: takeoff software by trade.
Common questions
What do the sheet letters mean?
Plan sheets are grouped by discipline with a letter prefix: A is architectural, S structural, M mechanical (HVAC), E electrical, P plumbing, and C civil or site. The number after the letter orders the sheets within that discipline.
How do I find the scale of a drawing?
The scale is noted in the title block or under each detail, for example 1/8 inch equals 1 foot. Always confirm it against a known dimension before measuring, and remember it can differ between sheets.
What is a schedule on a construction drawing?
A schedule is a table that lists items and their properties, such as a door schedule, fixture schedule, or equipment schedule. It tells you types and often expected quantities to check your takeoff against.