They need to conform to the design intent shown on the architectural and structural drawings, but they go into far more fabrication-level detail than the design drawings ever show. The design team reviews shop drawings specifically to confirm that added detail doesn't deviate from what was designed.
What Information Is Included in Shop Drawings?
Short answer: A shop drawing typically includes precise dimensions, material specifications, connection and fastening details, fabrication marks, installation sequencing, and coordination references with other trades - everything a fabricator or installer needs to build the component correctly without guessing.
That's the quick version. But the level of detail that goes into a good shop drawing is exactly what separates a submittal that sails through review from one that comes back marked “revise and resubmit.” Here's what actually goes into one, piece by piece.
The Core Elements Every Shop Drawing Should Have
1. Precise Dimensions
Architectural drawings often show dimensions rounded to the nearest inch or fraction, because they're communicating design intent at a project scale. Shop drawings go much further - dimensions down to 1/16th of an inch or finer, since fabrication tolerances at the shop level are far tighter than what's needed for a design-level drawing.
2. Material Specifications
Every shop drawing needs to call out exactly what material is being used: steel grade, gauge, finish, wood species, concrete mix design, glass type, and so on. This isn't a formality - it's what allows the fabricator to order the right stock and confirms to the reviewer that the specified performance requirements (fire rating, structural grade, weathering class) are actually being met.
3. Connection and Fastening Details
For structural and metal work especially, this is often the most heavily scrutinized part of the drawing. It includes bolt sizes and patterns, weld symbols and types, anchor details, and any special hardware. A missing or ambiguous connection detail is one of the most common reasons a structural shop drawing gets sent back during review.
4. Fabrication Marks and Piece Numbers
Large or complex projects - a structural steel package, for instance - involve dozens or hundreds of individually fabricated pieces. Shop drawings assign a piece mark to each one, so a beam fabricated in a shop can be correctly identified, shipped, and erected in the right location without confusion on-site.
5. Installation or Erection Sequence
Especially critical for structural steel and precast concrete, this shows the order in which components go up, along with any temporary bracing or support required during erection. Getting the sequence wrong isn't just an inconvenience - on structural work, it can be a genuine safety issue.
6. Coordination References
A well-prepared shop drawing doesn't exist in isolation. It cross-references other trades' work to flag potential clashes - a duct run that might conflict with a structural beam, for example - before fabrication starts rather than after.
7. Revision History and Submittal Tracking
Each submittal cycle should be clearly marked with a revision number, date, and a record of what changed from the previous version. On projects with multiple resubmittals, this tracking is what keeps everyone building from the current version instead of an outdated one.
8. Notes and Legends
Standard drawing notes, abbreviations, and symbol legends specific to the trade - welding symbols per AWS standards, for instance - so the drawing can be read correctly by anyone in the shop or field, not just the person who drew it.
What Trade-Specific Shop Drawings Typically Add
While the core elements above apply broadly, different trades layer in additional information:
- Structural steel shop drawings add bolt lists, camber requirements, and often a full erection plan showing crane positioning and sequencing.
- Precast concrete shop drawings include reinforcement layouts, embed and insert locations, and lifting/handling details specific to each precast piece.
- MEP shop drawings (particularly for coordinated/BIM-based MEP) include duct and pipe routing with exact elevations, equipment schedules, and clash-resolved coordination views across mechanical, electrical, and plumbing scopes.
- Curtain wall shop drawings include panel layouts, anchor and bracket details, sealant joint locations, and thermal break details.
- Millwork shop drawings include joinery details, hardware schedules, finish specifications, and full-scale profile sections.
What Should Never Be Missing
A few omissions come up often enough in practice that they're worth flagging specifically:
- Tolerances. Without stated tolerances, a fabricator is left guessing how tight a fit needs to be, which invites either costly over-engineering or field-fit problems.
- Cross-trade coordination notes. A drawing that's internally perfect but ignores adjacent trades is exactly how field clashes happen.
- A clear revision log. Missing this is one of the most common - and most preventable - causes of building from an outdated drawing version.
- Scale and reference to the governing design drawing. Every shop drawing should clearly reference which architectural or structural drawing it's detailing, so reviewers can cross-check it against design intent quickly.
Why This Level of Detail Matters
It's tempting to think of all this as bureaucratic thoroughness, but the level of detail in a shop drawing exists for a practical reason: it's the last checkpoint before material gets cut, welded, or cast. A dimension that's off by a fraction of an inch on paper is a five-minute correction. The same error caught after fabrication can mean scrapped material, schedule delays, and real cost.