Between “facade contractor appointed” and “first panel delivered” sits a package of drawings that most project teams underestimate. Shop drawings fix every dimension, joint, fixing and interface on the building. Get them right and fabrication is boring; get them wrong and the errors arrive on site as crates.
What a complete package contains
A shop drawing set is not a redrawn architectural elevation. It is the fabrication instruction for a specific building, referenced to a specific grid.
- General arrangement drawings: every elevation, with panel numbering and setting-out dimensions from the structural grid.
- Typical and special details at 1:5 or 1:2: head, sill, jamb, corner, expansion joint, parapet and soffit.
- Interface details with other trades: slab edge, roof, balustrade, louvre, door frame and any signage penetrations.
- Structural calculation package for mullions, transoms, brackets and anchors, signed by a qualified engineer.
- Glass and panel schedules: type, size, thickness, coating, and the location of every unique panel.
- Fixings and sealant schedule, with torque values and approved products.
Who reviews it, and how long it takes
The facade contractor produces the drawings; the architect reviews them for design intent, the structural engineer for load paths and anchors, and the main contractor for interfaces and programme. On complex projects a facade consultant sits between all three.
A clean first submission is approved with comments in two to three weeks. A submission with unresolved interfaces typically takes three rounds and eight to ten weeks, and every round pushes the production start date by the same amount.
The single biggest cause of delay is not drawing quality — it is an unresolved interface with another trade that nobody owns.
Five mistakes that cost weeks
- Issuing elevations without a survey of the as-built structure, so every dimension is nominal rather than real.
- Leaving the expansion joint strategy undefined, then discovering it during the mock-up.
- Specifying a coating or glass build-up that the approved supplier cannot actually produce in the required size.
- Submitting details before the interface with the roof or balustrade has been agreed with those trades.
- Approving a mock-up that differs from the shop drawings, which quietly makes the mock-up meaningless.
How BLTC handles drawings
We can detail from your architectural drawings or take your Revit model and return LOD 350 families with DWG details for approval. Every drawing set is issued with a transmittal that lists what changed since the previous revision, so reviewers are not re-reading the whole package to find three dimensions.
If a facade consultant is appointed, we coordinate with them directly. Routing technical comments through the main contractor is the fastest way to add a week to every review cycle.
Summary
Shop drawings are cheap compared with the cost of getting them wrong. Budget six to eight weeks for a clean approval, resolve interfaces before the first submission, and treat the approved set as the single source of truth for fabrication, mock-up and site inspection.