Architectural Sheets: The G and A Series

Welcome

Hello, and welcome. This is Super Structures General Contractors — a national general contractor headquartered in Powhatan, Virginia — here to help you and your clients build something that lasts. We're glad you're with us, and we look forward to connecting with you.

Alright, Architectural Sheets: The G and A Series. Don't let the plain title fool you. Here's the part that actually matters on the job: The G and A sheets are the master set every other discipline is drawn to match, and a reader who can follow a callout bubble from plan to section to detail to schedule can find anything in the building. Learn it well and you'll stop asking the architect what the drawings mean and start telling the subs.

We're working from a real four-story apartment set. Fundamentals covered the title block, scale, dimension strings, and basic symbols; this lesson goes sheet by sheet through the G and A series.

The G sheets and the code analysis

The G series opens the set. G-001 is the cover: the sheet index and often the deferred submittal list that tells you what is not designed yet. G-002 is the code analysis.

• Occupancy and construction type — an apartment building is R-2, usually Type V-A or III-A wood frame; the type drives every rating in the building.
• Allowable height and area — the math that lets this building be four stories, and the sprinkler type (NFPA 13 versus 13R) that makes it work.
• Rated assemblies table — exterior, corridor, unit separation, floor-ceiling, and shaft assemblies, each with an hourly rating and a listed design number.
• Life safety plans — rated walls hatched by rating, travel distances, exit counts, accessible unit locations.

Check that the rated-wall legend matches the wall type tags on the plans; every penetration and door rating traces back here.

Sheet numbering and how the A series is organized

Most offices follow a version of the national CAD standard: the letter is the discipline, the first digit after the dash is the sheet type, the rest is sequence. On this set: A-0 wall types and assemblies, A-1 floor plans, A-2 exterior elevations, A-3 building and wall sections, A-4 enlarged plans and the apartment unit plans, A-5 details, A-6 schedules. Offices vary; the index is the law.

On an apartment set, the overall plans are at 1/8 inch and cut by match lines, so one wall shows on two sheets, and each unit type (A1, B2) is drawn once at 1/4 inch on an A-4 sheet and referenced by a unit tag. Levels 2 through 4 are often one typical plan with a note listing the levels it covers; a typical plan that quietly excludes Level 4 is a classic miss.

Floor plans and reflected ceiling plans

Look at A-102, the Level 2 plan. Each wall carries a wall type tag pointing to the wall type sheet; each door has a door tag (often the room number plus a letter, like 204A) keyed to the door schedule; rated walls carry their hatch from G. Dimension strings run in tiers from the gridlines, and the general notes say whether they go to face of stud, face of finish, or centerline — one note that moves your layout by inches everywhere.

The reflected ceiling plan (RCP) is the same floor viewed as if the floor were a mirror: same orientation, door swings gone, and you see ceiling heights, soffits and bulkheads with their heights, ceiling materials, lights, diffusers, and access panels. A 12-inch soffit on the RCP under a 14-inch duct on the M sheet is a conflict to find on paper, not with a lift.

Elevations, building sections, and wall sections

Exterior elevations (A-201 series) carry grid bubbles across the top and level datums down the side — Level 1 at 100'-0", Level 2 at 110'-1 1/8" — with material tags and window types. Building sections (A-301) cut the whole building and show floor-to-floor heights, the roof structure, and how the foundation meets the frame. Wall sections (A-311) are the money view: one vertical slice of the exterior wall at large scale, footing to parapet, with the brick ledge, flashing, weather barrier, sheathing, truss bearing, rim, and fireblocking. The section cut symbol on the plan is a line with a bubble: top number is the section, bottom is the sheet. Check the level datums against the structural top-of-sheathing elevations; a 1 1/8-inch disagreement is a truss drawn one way and framed another.

Details and following a callout bubble

Finding a detail is a chain. On A-102 a bubble at the corridor wall reads 7 over A-501. Go to A-501 and find detail 7. The detail may send you further — see wall section 2/A-311 — so the chain usually runs plan to wall section to detail to spec section. Watch the modifiers: SIM means the detail applies with obvious differences, OPP HAND means mirrored, TYP means everywhere this condition occurs. A bubble that references 9/A-502 when A-502 has eight details is an RFI, not a guess.

Door, window, and finish schedules

The door schedule (A-601) has a row per door tag: size, door type keyed to the door elevations, material (HM, WD, AL), frame, fire rating (20-minute, 45, 90), hardware set number, and remarks. The window schedule gives type, rough opening, glazing, and performance values. The finish schedule goes room by room — floor, base, walls, ceiling — with a legend for the finish codes. Check that the door rating matches the wall rating on the plan (a 20-minute door in a 1-hour corridor wall is right; a non-rated door there is wrong) and the window rough opening agrees with the structural header schedule.

Going Deeper (Intermediate)

Know which set you are holding. The revision block lists deltas with dates, and a revision cloud with a delta shows what changed. After permit, changes come as ASIs, bulletins, or addenda, and the office may issue a conformed set that folds them in. The super's working set is the latest conformed set with every ASI posted, and the subs build from the same thing; two different sets in two trailers is how a rated wall gets built non-rated.

Advanced / Pro-Level

Architectural is the discipline the others draw over: structural matches its gridlines and exterior dimensions, and the MEP sheets draw on its background. When A and S disagree, find out which was updated last and get the other corrected. On apartment work, pros also read the unit matrix — how many of each type, which are mirrored, which are accessible Type A units — because a mirrored unit flips every wet wall, panel, and door swing.

Practice Challenge

On A-102 a bubble at the corridor wall reads 3 over A-511, and the wall carries tag W4. Where do you go, and what three things are you checking before that wall is framed? (Answer: detail 3 on sheet A-511 for the construction at that location; wall type W4 on the A-0 sheet for the assembly, its hourly rating, and its listed design number; then the door schedule for any door in that wall to confirm its rating matches the wall. If any of the three disagree, write the RFI before the framer starts.)

In Practice

A super who walks a floor with the plan, the RCP, and the wall type sheet open together catches the soffit conflicts and rating mismatches in an afternoon. A super who carries only the floor plan finds them when the inspector does.

Common Mistakes to Avoid

• Skipping the G code analysis and learning the ratings from the inspector
• Laying out to face of finish when the general note says face of stud
• Trusting a typical plan without reading which levels it covers
• Building a mirrored unit from an un-mirrored unit plan
• Guessing at a detail bubble that leads nowhere instead of asking

Takeaway: The G and A sheets are the master set every other discipline is drawn to match, and a reader who can follow a callout bubble from plan to section to detail to schedule can find anything in the building.

Educational content — not legal, safety, or contractual advice. Follow your company's procedures, your contract, and the OSHA and local requirements that apply to your site.