Fibre Reinforced Facade Encyclopedia: Manufacturing
Shop drawings are the fabricator’s own drawings of the facade as it will actually be made, produced after award and issued to the design team for review before any mould is cut or any panel is manufactured. They translate the architect’s design intent drawings into a panel by panel description: every unit numbered, every joint dimensioned, every fixing located, every tolerance stated. Approval of shop drawings is the point at which responsibility for buildability transfers, and on most facade packages it is the longest item on the critical path before production starts.
A 900 panel facade typically generates 60 to 150 shop drawing sheets and two to three review cycles, consuming 8 to 14 weeks between award and the release of the first mould.
At a glance
| Property | Typical value | Note |
|---|---|---|
| Issued by | The fabricator or specialist subcontractor | Not by the architect or the head contractor |
| Typical sheet count | 60 to 150 sheets for a mid rise facade | Layouts, panel types, sections, details, schedules |
| Review period | 10 to 15 working days per issue | Set in the contract; nominate it in the specification |
| Review cycles | 2 to 3 before status A | Each additional cycle costs 2 to 4 weeks of programme |
| Drawing scale | 1:50 to 1:100 for layouts, 1:5 to 1:10 for details | Full size for profiles and sealant joints |
| Model source | One federated 3D model at LOD 350 to 400 | The same model that drives CNC tooling |
| Panel tolerance stated | plus or minus 2 to 5 mm per panel dimension | Separate from setting out and site tolerance |
| Status codes | A, B, C or equivalent | A means make; B means make with noted amendments; C means resubmit |
| Programme position | Before mould making, after structural survey | A late survey delays every downstream item |
What shop drawings contain
A complete facade shop drawing set covers five things. First, elevations with every panel given a unique mark, keyed to a panel schedule. Second, setting out: gridlines, level datums, the relationship of panel joints to structural grid and to window openings, and the dimensional chain from the structure to the face of the panel. Third, panel details: thickness, profile, returns, rib or frame arrangement, weight, and the position of every cast in or laminated in insert. Fourth, fixings and interfaces, including the bracket, the substructure, movement allowance, flashings, sealant joint widths and the interface with adjacent trades. Fifth, tolerances, stated separately for manufacture, for the supporting structure and for site setting out.
The set is accompanied by documents that are not drawings but are reviewed with them: the panel schedule with weights, the fixing calculations and certification, material and finish samples, test reports for fire and structural performance, and the proposed mould type for each panel family.
How the review cycle works
Shop drawings are submitted for review, not for design. The reviewer is checking that what the fabricator proposes to make satisfies the documented design intent and the specification, not redesigning the facade at the fabricator’s expense. Most contracts use a status code system: status A or equivalent means proceed to manufacture, status B means proceed with the marked amendments incorporated, and status C means the submission is rejected and must be resubmitted.
Two habits cause most of the damage to programme. The first is a review turnaround that is not fixed in the contract, so the ten day review becomes six weeks. The second is a design team using the shop drawing review to make changes that were not in the tender documents, which resets the cycle and generates variation claims. Naming the review period, the number of cycles allowed and the status code definitions in the specification is the cheapest programme protection available.
The relationship to the model
On any facade with curvature or non-orthogonal geometry, the shop drawings and the manufacturing data come from the same 3D model. The drawings are a readable, checkable, signable view of that model; the model is what actually drives the CNC cutter, the nesting and the digital fabrication workflow. This is why the model has to be resolved before the drawings are issued, and why a change accepted verbally on site without returning to the model is a defect waiting to be discovered.
A survey of the as-built structure sits ahead of both. Structural frames are built to their own tolerances, which are looser than facade tolerances, so the fabricator surveys the actual slab edges and columns and adjusts panel dimensions and packing allowances before the drawings are finalised. Shop drawings prepared from design geometry alone, without a survey, are a common cause of panels that do not fit.
Shop drawings and liability
Approval does not transfer design responsibility for the base building or relieve the fabricator of its obligation to comply with the contract. In most Australian forms, the reviewer’s endorsement means the submission appears to conform to the design intent; it does not warrant dimensions the fabricator has taken off site, nor does it approve a departure from the specification unless that departure is explicitly identified and accepted in writing.
What a specifier should ask for
- A nominated review period in working days, and a maximum number of review cycles included in the price
- Panel weights on the schedule, so the crane lift planning and the supporting structure can be checked
- Fixing design certified by a registered structural engineer, with the wind load case used
- A dimensional tolerance table covering manufacture, structure and site setting out
- The mould strategy, showing how many distinct mould types the panel geometry reduces to
- Identification of any hold point, such as a mock-up or a signed control sample, and where it sits in the drawing programme
Standards and references
- AS 1100 series, technical drawing, for drawing conventions and dimensioning
- NATSPEC facade and cladding worksections, submissions and shop drawing clauses
- AS 3600 and AS 4100 for the structural verification supporting fixing design
- AS/NZS 1170.2 wind actions, for the load case shown on the fixing calculations
- AS 4284, facade testing, where a performance mock-up is a hold point in the drawing programme
- ISO 19650 parts 1 and 2, information management, where the project runs a BIM execution plan
Related terms
Questions specifiers ask
Who produces shop drawings, the architect or the fabricator?
The fabricator. The architect issues design intent drawings and a specification; the fabricator produces the panel by panel drawings showing exactly what will be made, and submits them for review.
How long does shop drawing approval take?
Allow 8 to 14 weeks from award to first mould release on a mid rise facade, covering preparation, a survey of the structure and two to three review cycles. Fixing the review period in the contract is the main control over that number.
Does approving shop drawings transfer design responsibility?
No. Endorsement confirms the submission appears to conform to the design intent. It does not warrant the fabricator’s site dimensions and it does not approve departures from the specification unless those are separately identified and accepted.
What is the difference between shop drawings and as-built drawings?
Shop drawings describe what will be manufactured and are issued before production. As-built drawings record what was actually installed, including any site amendments, and are issued at completion.
Can panels be made before shop drawings are approved?
They should not be. Manufacturing ahead of approval puts the cost of any change onto whoever authorised the early start, and on external walls it risks producing a system that the certifier will not accept.
Need a facade package documented panel by panel before it goes to tender? We produce shop drawings from the design model and can flag buildability issues early. Talk to our engineering team
Reviewed by Richard Halvorsen, General Manager, ShapeShift Technologies. Last updated September 2026.