How a drawing set is organized
A construction drawing set is divided by discipline, each with a letter prefix: G for general, C for civil, A for architectural, S for structural, M, P and E for mechanical, plumbing and electrical. Within each discipline, sheets usually run from general information to plans to elevations, sections and details. S-001 might be general notes, S-101 the foundation plan, S-201 and up the framing plans, S-301 elevations and S-501 details, though every engineer numbers a little differently.
Start with the sheet index on the cover sheet. Check that every listed sheet is in the set you received, and note sheets marked "not used" or "issued for reference". A missing sheet is easier to request on day one than the day before the bid.
Grids, dimensions and scales
Grid lines are the coordinate system of the building: usually numbers in one direction and letters in the other, with the dimensions between them strung along the edge of each plan. Columns sit at grid intersections, and most beam lengths can be checked against grid dimensions without measuring at all.
Each plan, section and detail has its own scale printed under its title. Check whether the set is full size or a reduced print before measuring, and favor written dimensions over scaled ones wherever they exist. Where a dimension is written, the written number governs; scaling is for what isn't dimensioned.
General notes: read them first, every time
The structural general notes apply to every member on the job and are where many cost drivers hide:
- Design criteria and codes, which tell you the building's loads and whether seismic detailing requirements may apply.
- Material specifications for each kind of steel: shapes, HSS, pipe, plate, bolts, anchor rods and weld filler metal.
- Connection design responsibility, including any delegated design and the reactions you must design for.
- Finish requirements: primer, galvanizing, or coatings for exposed or exterior steel.
- Special inspection and testing requirements, often with a separate schedule of special inspections.
- Typical details referenced from the notes, such as typical lintel or opening frame details that apply wherever conditions match.
Foundation plan: columns and anchor rods
The foundation plan locates every column by grid line, usually with a column mark or a base plate type. Pair it with the column schedule and base plate details to get each column's size, base plate, anchor rod pattern and elevations. Top of footing or pier elevations, together with the top of steel elevations on the framing plans, give column lengths.
Look for embedded items in the foundation and slab-on-grade details as well: embed plates, edge angles at slab depressions, and trench frames.
Framing plans: where most of the tonnage is
Each framing plan shows one level's beams, girders, joists and deck, viewed from above. Key notation to recognize:
- Size tags along each member, such as W18X35. Columns appear as small symbols at grid intersections, sized in a schedule or tagged directly.
- Shear studs and camber, commonly written next to the size: W21X44 (24) c=3/4" means 24 studs and 3/4" of camber. Check the legend; conventions vary by engineer.
- Top of steel elevations, given in a general note for the level and called out where a beam steps up or down.
- Moment connection symbols at beam ends, usually a small triangle or filled marker, defined in the legend.
- Joist designations such as 18K5 or a joist girder callout, with spacing.
- Existing members, often marked (E) or drawn dashed. Usually not in your scope, but they may need new connections.
- "TYP." and "SIM." notes, which tell you a condition repeats. Find every place it applies.
Openings in the deck, framed with angles or channels, are often shown only by a small rectangle with a reference to a typical detail. Count them.
Elevations, sections and details
Plans show where members are; elevations, sections and details show what happens in the vertical direction and at the connections.
- Frame elevations show braced frames and moment frames: brace sizes, gusset plates, work points and story heights. Brace lengths come from here, not the plan.
- Sections cut through the building show members that plans can't, such as hangers, posts, and steel at sloped or stepped roofs.
- Details show connections, base plates, lintels, ledgers, embeds and edge conditions. A callout bubble on a plan gives the detail number over the sheet number, so 4/S-501 is detail 4 on sheet S-501.
Read details for scope, not just for connection geometry. A slab edge detail may show a continuous bent plate around the whole floor, which is a lot of steel that never appears on the framing plan.
Schedules
Schedules collect repeated information in tables, and they are fast to take off from because they are already organized. Common steel schedules include:
- Column schedule: size by column mark and level, with splice locations.
- Base plate and anchor rod schedule: plate size and thickness, rod diameter, length and count.
- Lintel schedule: lintel mark, angle or plate sizes, and bearing length for each opening width.
- Joist schedule: designations and special loads that the joist supplier must design for.
Make sure every mark in the schedule is taken off as many times as it appears on the plans and elevations, and that every mark on the plans exists in the schedule.
Architectural, mechanical and civil sheets
Much of the miscellaneous metals scope lives outside the structural set. Architectural sheets show stairs, railings, ladders, canopies, lintels on elevations, wall openings and support framing for finishes. Mechanical sheets show rooftop units and equipment that need frames or dunnage. Civil and site sheets can show bollards, site railings, trench grating and gates.
When an architectural detail says "steel support by structural" and the structural set shows nothing, that's a scope gap. Write it down for an RFI or a clarification in your proposal.
Specifications
The project manual tells you how the steel must be made and finished. In Division 05, read the sections for structural steel framing, steel joists, steel decking, metal fabrications, metal stairs and metal railings. Look for submittal requirements, delegated design, fabricator and erector qualifications, coating systems, field touch-up, and testing.
Division 01 matters too: schedule, temporary facilities, cleanup, closeout documents and allowances. Where the drawings and specification disagree, the contract usually says which governs. Price the more expensive requirement or clarify it in your proposal.
Addenda, revisions and bulletins
Addenda are issued during bidding and become part of the contract documents. They may reissue whole sheets or describe changes in text. After award, changes come as bulletins, ASIs or revised sheets.
Revised sheets usually mark changes with clouds and a delta symbol with the revision number, but don't rely on the clouds alone; not every change gets clouded. Compare the old and new sheets directly, and update your drawing log so takeoff on a superseded sheet can't slip through.
Kredna flags new and changed drawings as soon as they land in the job folder, groups them into drawing sets with the superseded sheets marked everywhere, and compares revisions as a color overlay with every changed area boxed. See drawing revisions.
Reading for what isn't shown
The most valuable reading skill is noticing what's missing: a stair with no stringer size, a railing with no post spacing, a canopy with no framing, a connection left to the fabricator with no reactions. Each one is either an RFI before bid, an assumption in your proposal, or a risk you price on purpose.
Keep a running list as you read and turn it into clarifications. Kredna's optional AI drawing scan can act as a second set of eyes, pointing out possible steel scope on the pages you choose with the evidence for each finding, for you to take off or dismiss.