The discipline letters
- G. General: cover sheet, sheet index, code information.
- C. Civil: grading, utilities, paving.
- L. Landscape: planting and irrigation.
- S. Structural: foundations, framing, structural details.
- A. Architectural: plans, elevations, sections, schedules.
- I. Interiors, on some jobs.
- F or FP. Fire protection.
- P. Plumbing.
- M. Mechanical, which covers heating, ventilation and air conditioning.
- E. Electrical: power, lighting, panel schedules.
- T. Telecommunications or technology.
Some sets add a second letter. AD is often architectural demolition. FA is often fire alarm. Read the sheet index, because offices vary.
What the digits mean
Many architects follow a common standard. The first digit after the letter gives the sheet type. The last digits count the sheets in order.
- 0. General notes, legends and symbols.
- 1. Plans.
- 2. Elevations.
- 3. Sections.
- 4. Enlarged plans and large-scale views.
- 5. Details.
- 6. Schedules and diagrams.
Under that standard, A-101 is the first architectural plan and A-601 is the first architectural schedule sheet. Many offices use their own system, such as A2.11 for a floor plan. The sheet index on the cover is the only reliable guide.
The usual order of a set
A set usually runs general, civil, landscape, structural, architectural, then fire protection, plumbing, mechanical and electrical. Specialty sheets such as food service or athletic equipment often sit near the architectural sheets.
How to use sheet numbers on a bid
- Open the sheet index and mark each sheet that could show your work.
- Check the index against the files you have. Find missing sheets.
- Record the sheet number beside each count in your takeoff.
- Use sheet numbers in every question you send to the architect.
- When an addendum reissues a sheet, replace the old one and note the date.
Bid documents · Updated 11 Nov 2026