Approval Drawings
Approval Drawings vs Design Drawings: Roles, Differences and Coordination
How structural design drawings and steel approval drawings differ, who owns each, and how to coordinate them without silent redesign.
Design drawings and approval drawings can look similar: plans, elevations, member sizes. They are not the same document. The design drawing states structural intent under the engineer of record. The approval drawing states the fabricator’s interpretation of how that intent will be manufactured and, in some contracts, how connections will be completed.
Confusion between the two sets causes two opposite failures. The fabricator treats the design drawing as a shop drawing and invents missing holes. Or the detailer treats the approval drawing as a licence to change member sizes because “it fits better in CAD.”
This article separates roles and describes a coordination path. It pairs with shop versus approval and what approval drawings are.
Different authors, different questions
| Design drawing | Approval drawing | |
|---|---|---|
| Author | Engineer of record / designer | Fabricator or detailing office |
| Question | Is the structure adequate for the stated criteria? | Has the fabricator understood and proposed a buildable interpretation? |
| Connections | Often typical or performance-specified | Often completed in detail, if assigned |
| Piece marks | Rare | Usual |
| Revision driver | Design change | Fabricator interpretation and reviewer comments |
Coordination rules that prevent silent redesign
If approval drawings need a different member size, that is a substitution request, not a CAD convenience. Log it. If the design drawing is unclear, RFI. If the approval drawing finds a clash the designer missed, send it back as information the designer owns — then wait for an issued design change before moving steel.
- Cite the design issue letter on the approval cover
- Do not erase design notes that still apply
- Show substitutions in a list, not only as a quietly changed size
- Keep load and code criteria on the design set; repeat them on approval notes only as required for the submittal
Level of detail
Design drawings may omit hole patterns. Approval GAs may omit them too, pointing to typicals. Shop drawings add them. Expecting design drawings to include fabrication-level holes is a specification issue, not a moral failure of the designer. Read the project’s drawing requirements.
When the same person wears both hats
On some design-build jobs the same office designs and details. Even then, keep the design issue and the approval issue as separate stamps and separate questions. Mixing them makes it impossible to see whether a change was a design decision or a shop preference.
PEB programmes
PEB manufacturers often produce both analysis and approval packages internally. The owner’s engineer may still review the approval set against performance specifications. Coordination is then about reactions, geometry and specified loads, not about redrawing every web member by hand. See PEB design coordination.
A practical workflow
- Issue design drawings with a letter.
- Detailers cite that letter and raise RFIs for gaps.
- Approval package interprets; does not silently redesign.
- Reviewer comments; substitutions logged.
- Design changes re-issue; approval back-checks against the new letter.
Engineering tips
- Keep a substitution log even if it has zero rows. The empty log is a statement.
- When overlaying CAD, lock the design underlay so it cannot be edited as if it were yours.
- If a clash is found, send a sketch back on the design’s grid, not only a shop mark.
Common mistakes
Changing a beam size to match a stock length without telling the designer
That is a design change.
Reviewing approval drawings as if they were a full design check
The reviewer should know the stamp’s scope. Over-claiming review is as bad as under-reviewing.
Letting approval notes overwrite the specification
The specification still governs unless a change order says otherwise.
Checklist
- Design issue cited
- Roles clear on the cover
- Substitutions logged
- RFIs for gaps, not guesses
- No silent member-size edits
- Comments mapped to design vs fabrication
Frequently asked questions
Which set does the builder construct from?
Usually the issued-for-construction design drawings plus the approved fabrication/erection documents. The contract decides. Do not assume.
Can approval drawings be more detailed than design drawings?
Yes. That is often the point. They should not contradict the design.
Who owns a clash found in detailing?
The clash is information. The design change, if any, belongs to the designer. The detailing change belongs to the detailer after that issue.
Does software merge these sets?
Some BIM workflows share a model. You still need to know which issue was stamped as design and which as approval.
Where this leaves the work
Keep the questions separate. Design asks “is this the right structure?” Approval asks “have we interpreted it in a way the shop can build?” Mixing the questions is how responsibility evaporates.
For the package itself, return to what approval drawings are and the approval process.
This article provides general educational information. Project-specific structural design, calculations and drawings should be reviewed by appropriately qualified engineering professionals and checked against applicable project requirements and standards. StruTools does not replace engineering judgement or professional design review.