Design drawings tell the fabricator what the building must do. Shop drawings tell the workshop exactly what to cut, drill, weld and paint, piece by piece. A pre-engineered metal building (PEB) of 5,000 m² typically needs 150–300 shop drawing sheets. A high-rise package can exceed 5,000.
This guide explains what a complete shop drawing set contains, which drawing types you should expect, the NC and BOM files that go with them, a checklist for reviewing them, and how the approval cycle works on our projects.
- Design vs shop drawings
- GA, erection, assembly and part drawings
- NC/DSTV files and BOM
- Review checklist
- Review and approval cycle
- Sample drawing set (PDF)
- FAQ
Written by the Guiguan Steel Engineering Team. Published October 2026. Figures are typical values and are confirmed per project in our quotation.
Design drawings vs shop drawings
Shop drawings sit between the engineer’s design and the fabrication floor. They are produced from a 3D model, usually in Tekla Structures, after the design is frozen.
| Design drawings | Shop drawings | |
|---|---|---|
| Prepared by | Engineer of record | Fabricator’s detailer |
| Purpose | Show structural intent and member sizes | Give every dimension needed to fabricate and erect |
| Connections | Typical details or design forces | Every bolt, hole, plate and weld fully dimensioned |
| Units of issue | By grid / elevation | By piece mark, assembly and erection zone |
| Approval | Building authority | Engineer of record and client |
| Output files | PDF / DWG | PDF, DWG, NC (DSTV), IFC, BOM |
If your design drawings only show typical connections, the detailer designs or completes the connections to your design forces. We do this to AISC 360, EN 1993 or AS 4100 as specified, and send calculations with the first submission. More on our BIM steel detailing service.
What a shop drawing set contains
A complete set has four levels of drawing, from the whole building down to a single plate.
General arrangement (GA) drawings
Plans, elevations and sections showing every member by piece mark on its grid. GA sheets include the anchor bolt plan, roof and wall bracing plans, purlin and girt layouts, and the column base reaction table used by the foundation contractor.
Erection drawings
Isometric and elevation views grouped by erection zone or sequence. They show piece marks, orientation, bolt grades, tightening method, site welds and erection tolerances. Each member’s mark on the drawing matches the stencil or tag on the steel.
Assembly drawings
One sheet per assembly, for example a tapered rafter with its end plates, stiffeners and purlin cleats. Assembly drawings show overall length, camber, hole groups, weld symbols to AWS A2.4 or ISO 2553, surface preparation, coating and weight.
Part (single-part) drawings
Flat plates, stiffeners, cleats and gussets with their profile, thickness, grade and hole positions. In a modern shop most parts are cut directly from NC files and these drawings serve as the QC reference.
| Drawing type | Typical scale | Sheets for a 5,000 m² PEB | Main user |
|---|---|---|---|
| GA and anchor bolt plan | 1:100 – 1:200 | 8–15 | Client, foundation contractor |
| Erection drawings | 1:50 – 1:100 | 15–30 | Erection crew, supervisor |
| Assembly drawings | 1:10 – 1:25 | 80–180 | Workshop fitters and welders |
| Part drawings | 1:5 – 1:10 | 40–100 | Cutting and QC |
Typical values for a single-storey PEB warehouse. Sheet counts vary with frame count and connection types.
NC files, DSTV and the bill of materials
The drawings are only half of the package. The workshop runs on data files exported from the same model.
NC files in DSTV format
DSTV (.nc1) is the standard format for CNC drilling, sawing and plasma or oxy-fuel cutting lines. One file per part holds the profile, length, hole positions, cut angles and markings. Plate parts can also be exported as DXF for nesting.
Bill of materials (BOM)
The BOM lists every assembly and part with profile, grade, length, quantity and weight. We issue it in Excel with three views: by assembly (for fabrication), by material (for plate and section purchasing) and by shipment (for packing lists). Our BOM weight is typically within 2% of the final weighed tonnage.
Bolt list and IFC model
The bolt list gives grade, diameter, length, washers and quantity per connection, plus about 3–5% spares. An IFC export lets your engineer or main contractor check the model in their own software and coordinate with MEP and concrete.
A 10-point checklist for reviewing shop drawings
Reviewing 200 sheets is slow. Focus on the items that cause most site problems. This is the checklist our own checkers use before a set goes out.
- Grids and levels match the architectural and structural drawings, including finished floor and top-of-steel levels.
- Anchor bolt plan: diameter, projection, grade, template and setting tolerance agree with the foundation drawings.
- Member sizes and grades match the design: Q355B, S355JR or A572 Gr.50 as specified. See our grade equivalence chart.
- Connections: bolt grade (8.8 / 10.9), quantity, edge distances and tightening method (snug-tight or pretensioned).
- Welds: CJP vs fillet, sizes and inspection class. CJP welds receive 100% UT.
- Camber and tolerances on long rafters, crane girders and trusses.
- Openings for doors, louvres, skylights and MEP penetrations are framed.
- Coating system, DFT and areas to be left bare for slip-critical faces or site welds.
- Shipping lengths: splices placed so no piece exceeds 11.8 m unless break-bulk is agreed.
- Revision cloud and table on every changed sheet.
Marked-up PDFs are the fastest way to return comments. A comment on a GA sheet is easier for us to trace than an email list.
The review cycle, step by step
Most delays happen in the review loop, not in detailing. Two review rounds is normal. More than three usually means the design was not frozen.
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Model and first issue
5–10 working days after design freeze for a typical PEB. We issue GA, anchor bolt plan and connection calculations first so foundations can proceed.
-
Client and engineer review
Usually 3–5 working days. Comments are returned as marked-up PDF. Status: Approved, Approved as noted, or Revise and resubmit.
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Revision and re-issue
1–3 working days. Changed sheets carry a revision letter and clouded changes. Unchanged sheets are not re-issued.
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Approved for construction
Sheets are stamped Rev 0 / AFC. Material is ordered and NC files are released to cutting lines.
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Fabrication and as-built
Fabrication runs 25–40 days after approval. Final drawings and BOM reflect any site or workshop changes.
Piece marks and revisions
Each assembly gets a unique piece mark, for example C12 for a column or R4-2 for the second rafter segment on frame line 4. The same mark is printed on the drawing, stencilled on the steel and listed in the BOM and packing list. Revisions run A, B, C during review and become 0 when approved for construction.
On a recent warehouse package of 2,400 t, the first issue went out in 8 working days and the set was approved after the second round. The JD Asia No.1 smart warehouse and the CGN Headquarters show the range from PEB to multi-cavity high-rise detailing.
What is in our sample drawing set
The sample set is taken from a real single-storey PEB warehouse, with client and site data removed. It contains:
| Sheet group | Contents |
|---|---|
| GA-01 to GA-06 | Anchor bolt plan, roof bracing, wall bracing, purlin and girt layout, column reactions |
| E-01 to E-04 | Erection elevations by frame line with piece marks and bolt schedule |
| A-series | Tapered column and rafter assemblies, haunch and ridge connections, crane bracket |
| P-series | End plates, stiffeners, cleats, base plates |
| BOM | Excel BOM by assembly, by material and by shipment |
| NC sample | DSTV .nc1 files for one frame |
Use it to compare against what other suppliers send you, or as a template for what to specify in your tender. For heavy steelwork, see structural steel fabrication. For the members in the set, see H-beams and plate girders and purlins, stairs and platforms.
Download sample drawing set BIM detailing service
The sample set is sent by email after a short request, so we can include the version that matches your code (AISC, EN or AS).
Questions engineers ask about this topic
Need a project-specific answer? Our engineers reply within 24 hours.
Who prepares the shop drawings, you or us?
We do. Our detailing team models the structure in Tekla Structures from your design drawings and issues shop drawings, NC files and BOM. Detailing is included in the fabrication price for projects above our 50 t MOQ.
How long does a shop drawing set take?
A typical PEB warehouse takes 5–10 working days for the first issue. High-rise or complex truss packages are issued in zones, starting with the first erection sequence.
Can you work from my Tekla or IFC model?
Yes. We import Tekla, IFC and DWG. If your model is already detailed, we check it, add workshop data and export NC files and BOM directly.
Do shop drawings need the engineer of record’s approval?
On most projects, yes. The engineer of record checks that the connections and members match the design intent. We do not release material for cutting until the set is approved for construction.
