The relationship, precisely
AIA A201 groups contractor submissions into shop drawings, product data, and samples — collectively, submittals. In day-to-day usage, people say 'submittals' when they mean the product-data packages and 'shop drawings' when they mean fabrication drawings, which causes the confusion this page exists to settle. Contractually they travel through the same review pipeline, get the same action stamps, and carry the same rule: approval does not shift design responsibility onto the reviewer, and it does not cover deviations you didn't flag.
When shop drawings are required
Shop drawings show project-specific fabrication or installation that catalog literature cannot. Typical scopes:
- Structural steel and rebar: piece drawings, bar bends, connection details
- HVAC ductwork: routing, gauges, coordination with structure and other trades
- Electrical gear: switchboard and panelboard elevations, bus layouts
- Curtain wall and storefront: elevations, sections, anchorage
- Millwork and casework: dimensioned fabrication drawings
- Fire sprinkler: full piping layouts with hydraulic calculations (delegated design)
How review differs between the two
Product data review is a conformance check: does the submitted model meet the specified performance and options? It is relatively fast. Shop drawing review is a design-coordination check: the engineer verifies the fabricator correctly interpreted the design, dimensions reconcile with the drawings, and interfaces with other trades work. It takes longer, generates more comments, and more often runs a second cycle. Schedule accordingly — shop-drawing scopes are where review float disappears.
One more practical difference: an error on approved product data usually means returning a product; an error on approved shop drawings can mean cutting up fabricated steel. That asymmetry is why reviewers are conservative with shop drawings and why dimension checking before submission pays for itself.
Who draws shop drawings
The fabricator or specialty subcontractor produces them — steel detailers, sheet-metal shops, curtain wall engineers, sprinkler designers. Some scopes are delegated design, where the sub's licensed engineer seals calculations along with the drawings. The GC still reviews and stamps before forwarding, and the design team's review is for conformance with design intent, not a re-check of the fabricator's arithmetic. Detailing capacity is a real constraint here: good steel and duct detailers book out weeks ahead, so the shop-drawing clock starts at buyout, not at the submittal deadline.
Where Submittal.App fits
Submittal.App automates the product-data side — matching schedules to manufacturer cut sheets and assembling formatted packages in minutes — and manages the whole register either way: shop drawing PDFs merge into the same packages, the same review links, and the same version history, so the log shows one coherent record per spec section. The terminology distinction stops mattering operationally when both types live on one timeline with one numbering scheme.