Approval Drawings — Purpose and Content
Approval drawings (sometimes called 'submittal drawings') are submitted to the engineer of record before fabrication begins. Their purpose is to demonstrate that the proposed detailing — connection types, member sizes, material grades — complies with the structural design. Approval drawings are typically less detailed than shop drawings: they show framing plans, connection types, and general arrangement rather than every hole location and weld symbol. The EOR reviews and stamps the approval set, granting permission to proceed with fabrication.
Shop Drawings — Purpose and Content
Shop drawings are the fabrication documents — the drawings the shop uses to cut, drill, weld, and assemble each member. They contain every dimension, hole location, bolt pattern, weld symbol, material grade, surface preparation note, and piece mark needed to fabricate without additional information. Shop drawings are extracted from the same 3D model used to produce approval drawings but carry more detail and are issued after approval is granted.
The Sequence and Why It Matters
The sequence is always: model → approval drawings → EOR review → approval → shop drawings → fabrication. Skipping or compressing this sequence — releasing shop drawings before approval is granted — means fabricating steel that may require changes based on EOR review comments. Any steel fabricated before approval that must be revised is typically at the fabricator's expense. In seismic zones and on public projects, inspectors may require documentation that fabrication was not started on unapproved drawings.
What Level of Detail Appears on Approval Drawings
Approval drawings for structural steel typically include: framing plans at each floor level showing member sizes and orientations; elevation views of braced frames and moment frames showing connection type designations; column schedules with section sizes and splice locations; and connection type details showing the general approach — end plate, shear tab, clip angle — without every bolt dimension. The EOR's review at this stage is focused on structural compliance and scope completeness, not on verifying hole-by-hole dimensions. That verification happens at the shop drawing stage after the connection approach is locked in.
EOR Review Stamps and Their Meaning
EOR approval stamps carry specific meanings that affect what the fabricator can do next. 'Approved' means the drawings may proceed to fabrication as shown. 'Approved as Noted' means fabrication may proceed after the noted revisions are incorporated — the detailer must revise the drawings, document the revisions, and confirm with the fabricator PM before releasing. 'Revise and Resubmit' means fabrication cannot begin on the affected items; the drawings must be corrected and resubmitted for another review cycle. 'For Information Only' means no fabrication authorization is granted — typically used for reference or coordination documents. Each stamp has different downstream implications and must be interpreted accurately.
Connection Calculations and the Approval Submittal
When connection design is delegated to the fabricator or their engineer, the approval submittal typically includes both the approval drawings and the signed and sealed connection calculations. The EOR reviews the calculations for load compliance and specification conformance — not for engineering correctness, which is the responsibility of the PE who signed them. The connection calculations and the approval drawings should reference each other: the drawing should show the connection as designed in the calculations, and the calculation cover sheet should list the drawings it supports. A submittal where calculations and drawings tell different connection stories is a first-cycle rejection.
How Approval Drawings and Shop Drawings Differ in Practice
The practical differences between approval drawings and shop drawings are substantial. Approval drawings show a framing plan with 'W24x62 beam, see connection detail type S-3' — the shop drawing for that beam shows the exact length, both end preparations, the cope dimensions, all hole locations with edge distances, the bolt callout, the surface preparation note, and the paint callout. An ironworker in the field might reference an approval drawing to confirm a member's overall size and connection type; they cannot fabricate from it. The production floor requires the shop drawing, and should never receive approval drawings as production documents.