Curtain Wall Shop Drawings: What the Package Must Contain and How It Clears Review

A curtain wall shop drawings package is the longest-lead, highest-risk submittal on most tall buildings in the Gulf. It is the only package where the contractor’s engineer designs part of the building, where a single missed millimetre of thermal movement shows up as a cracked seal three summers later, and where fabrication cannot start until a stamped set of structural calculations has cleared review. This guide covers what the package must contain sheet by sheet, how unitized and stick systems change its content, how thermal movement and tolerance stack-up are detailed for a 50 °C climate, and the eight reasons facade packages come back rejected.

What a Curtain Wall Shop Drawing Actually Is

A curtain wall shop drawing is a fabrication-level and installation-level drawing set, prepared by the facade specialist contractor or its detailing consultant, showing exactly how a specific curtain wall system will be manufactured, anchored to the structure and installed on a specific building.

The architect’s facade drawings establish what the envelope must be: the module, the sightlines, the performance criteria, the visual result. The shop drawing establishes how one particular system — a named profile series, a named glass makeup, a named anchor — delivers that result on this structure with its actual tolerances. The two documents have different authors, different purposes and different contractual weight.

Because the set is reviewed and stamped before anything is extruded or cut, facade contractors sometimes call it the “approval drawings” package, distinguishing it from the internal fabrication drawings that follow after approval. Both are shop drawings in the contractual sense; only the first goes to the consultant. The wider mechanics of that process — submittal registers, review outcomes, status codes and what a review stamp does and does not cover — are set out in our guide to the shop drawing submittal cycle in construction.

Why Curtain Wall Is Not Like Every Other Shop Drawing Package

Four characteristics separate facade packages from steel, rebar or MEP submittals, and each one changes how the drawings must be prepared.

Part of it is delegated design. On most curtain wall specifications the architect defines performance — design wind pressures, deflection limits, movement allowances, water and air infiltration criteria — and the facade contractor’s own engineer designs the system to meet it, submitting signed and sealed structural calculations alongside the drawings. The engineer of record reviews those calculations for conformance with the specified criteria rather than re-performing the analysis. That means the drawing set and the calculation set have to agree with each other exactly, and both have to agree with the structural engineer’s stated wind pressures.

It is procurement-critical. Glass and aluminium are long-lead items. Published trade guidance on glazing submittals puts fabrication lead times commonly at eight to sixteen weeks after approval, and longer for custom finishes or oversized lites — which is why the glazing package is normally among the first major submittals raised on a job. Treat those figures as indicative rather than fixed: they move with market conditions, mill capacity and finish type, and should be confirmed with your actual supplier for the actual project.

It carries more review cycles than most. The same guidance notes that two review cycles are normal on curtain wall, because three parties review different things: the architect reviews design and performance, the structural engineer reviews the delegated calculations, and physical finish samples add a separate approval loop with its own duration.

It closes before the structure is finished. Embed and bracket locations have to be issued while the frame is still being cast or erected. That single fact drives the anchorage sequencing described below, and it is the reason a facade package is usually split into at least two submissions rather than one.

Unitized vs Stick vs Semi-Unitized: How the Package Changes

Facade detailing providers typically cover unitized, semi-unitized, stick, mullion-and-panel, window wall and storefront systems. The system type is not a footnote on the cover sheet — it changes the content, the sequencing and the tolerance strategy of the entire drawing set.

The practical consequence: a unitized package is dominated by panel schedules and anchor survey reconciliation, while a stick package is dominated by setting-out and site sequencing. Submitting a unitized job with stick-system logic — no panel numbering, no as-built anchor reconciliation — is one of the more common structural weaknesses in a facade submittal.

The Sheet-by-Sheet Anatomy of a Curtain Wall Package

Package size varies enormously with geometry. One facade engineering practice notes that for a typical flat facade on a high-rise tower, a package of around a dozen drawing sheets can be sufficient at tender stage — a useful reminder that the tender-stage set and the full approval set are different animals. A full approval package on a complex tower runs to hundreds of sheets.

Whatever the size, a complete set is built from the same eleven categories.

Sheets 5, 6 and 8 are where the engineering actually lives, and where the level of drafting maturity is most visible. The two-dimensional content added over model views — gaskets, sealant profiles, membrane laps, standard notes — follows the same conventions as any other construction detail drawing. Sheet 10 is the direct procurement output, and on a modelled package it is generated from the same source as the construction bill of materials.

Anchorage and Embed Detailing

The connection between the facade and the frame is the single most consequential detail in the package, because it carries wind load, self-weight, seismic demand and thermal movement simultaneously — and because it is usually the first thing released.

Established facade engineering practice is to issue embed and bracket layout drawings as a separate, earlier deliverable: plans showing the shape and location of the metal connectors cast into a concrete frame, or the brackets attached to a steel frame, typically presented on a few sheets per floor. Those drawings have to be approved and in the hands of the structural contractor before the relevant floor is poured. Miss that window and the recovery options are post-fixed anchors, which have to be re-engineered and re-approved.

What the anchorage sheets must show:

• Bracket type and adjustability — the range of movement available in each axis, which is what absorbs the difference between the designed slab edge and the built one
• Substrate and edge distance — anchor capacity in concrete depends on edge distance and reinforcement congestion, and both need to be shown, not assumed
• Fixing schedule — type, size, centres, embedment depth, and torque where the system requires it
• Load path back to the calculations — every bracket type on the drawing should be traceable to a case in the delegated design submission
• Movement provision at the bracket — slotted holes, sliding connections or bearing arrangements, and which direction each one is free to move in

Thermal Movement and Tolerance Stack-Up in Gulf Conditions

This is the section most curtain wall content skips, and the one that matters most on projects in Riyadh, Jeddah, Dubai and Abu Dhabi.

Aluminium moves with temperature. The coefficient of linear thermal expansion for structural aluminium alloys is commonly taken as approximately 23 × 10⁻⁶ per °C — a figure published in aluminium design standards and materials references, and one that should be confirmed against the specific alloy and the applicable design code for your project rather than assumed. A dark-finished mullion on a west-facing elevation in the Gulf can swing through a surface temperature range considerably wider than the ambient air range, because solar gain on the metal adds to it.

The consequence for the drawings is not abstract. Over a floor-to-floor mullion length, a temperature swing of that magnitude produces movement measured in millimetres — small in isolation, cumulative over a facade run, and entirely capable of shearing a sealant joint or seizing a splice if the detail does not release it.

What the drawings have to show

• Mullion splice detail — the expansion joint between vertical members, with the gap dimension stated and the sleeve or spigot arrangement drawn, not implied
• Installation temperature note — the gap set at installation depends on the temperature at the time of installation, so the drawing needs a stated reference temperature and an adjustment table
• Direction of freedom at each anchor — one anchor per panel or per mullion run normally fixes the member; the others must be free to slide. Which is which has to be unambiguous on the sheet
• Glass edge clearance — the bite and edge clearance that allows the frame to move without loading the glass
• Sealant joint width and movement capability — joint width sized against the calculated movement and the sealant’s stated movement capability, both referenced on the drawing

Tolerance stack-up

Separately from thermal movement, the package has to absorb construction tolerance. Three tolerance sets meet at the facade line: the structural frame as built, the curtain wall fabrication tolerance, and the installation setting-out tolerance. Each has a permitted range under its own standard, and they do not cancel out — in the worst case they accumulate.

The practical test for a facade shop drawing is simple: can a reader determine, from the drawing alone, the maximum and minimum built condition the detail will still work in? If the joint is shown as a single dimension with no range, the detail has not addressed tolerance — it has assumed it away.

Glass Makeup and Performance Data on the Drawings

The glass schedule is reviewed against two separate criteria: appearance, and the performance values the building was permitted under. Trade guidance on glazing submittals is explicit that the values submitted should come from the fabricator’s or coating manufacturer’s calculation tool for the actual makeup, rather than from a brochure’s best-case configuration.

What belongs against every glazing type:

• Full IGU makeup, lite by lite — outer lite thickness, coating and its surface position, cavity dimension and gas fill, inner lite thickness, laminate interlayer where used
• Heat treatment per lite — annealed, heat-strengthened or fully tempered. Heat-strengthened is often preferred where safety glazing is not mandatory, because it resists thermal stress with less risk of spontaneous breakage and less roller-wave distortion; tempered is used where a safety glazing requirement applies
• Thermal and optical performance — U-value, solar heat gain coefficient and visible light transmittance for the assembly, plus acoustic ratings where specified
• Spandrel build-up — opacifier type, back pan, insulation and its interface with the vision glass line
• Edge and spacer detail — spacer type, primary and secondary seal, and edge deletion where a coating requires it

Which performance framework applies in the Gulf

Much of the published guidance on glazing submittals is written against the North American framework — the International Building Code for safety glazing locations, and NFRC procedures for reported thermal values. Projects in Saudi Arabia and the UAE work to a different set.

• Saudi Arabia — the Saudi Building Code, including its energy provisions, sets the baseline, with Civil Defence requirements applying to fire-related aspects of the envelope
• Dubai — Dubai Municipality’s green building regulations and the Al Sa’fat rating system apply, alongside the fire and life safety code for facade materials and compartmentation
• Abu Dhabi — the Estidama Pearl Rating System applies alongside the emirate’s building code framework

Weatherproofing Details Reviewers Look For

Watertightness and airtightness are what the facade is ultimately judged on, and the drawings are where the strategy is either legible or absent. A complete set identifies every silicone sealant joint, EPDM gasket and interface material, showing where each is applied, the joint width, and the sequence in which weatherproofing is built up.

Five things a facade reviewer will look for specifically:

• A continuous air and water barrier line — drawn as a single traceable line through every section and every perimeter detail, including where the facade meets slab edges, roofs and adjacent construction
• Pressure equalisation and drainage — weep paths, drainage channels and the route water takes out of the system, shown rather than described in a note
• Thermal break and condensation control — thermal break position, insulation zones and vapour control, which in a Gulf climate is a summer condensation risk on the interior side rather than the winter risk assumed in most published detailing guidance
• Sealant compatibility and adhesion evidence — sealant submitted without compatibility and adhesion testing against the actual glass, gasket and finish is a documented and common rejection reason
• Firestopping at the slab edge — the perimeter fire barrier between the facade and the floor slab, its interface with the facade insulation, and the interface with the spandrel back pan

Mock-Ups: VMU and PMU as Hold Points

Facade packages are one of the few submittals where a physical test sits between approval and production.

A visual mock-up (VMU) confirms appearance — finish colour, glass tint, sightlines, joint quality. A performance mock-up (PMU) is a laboratory test specimen subjected to air, water and structural load testing before the system is released for full production. Full performance mock-up testing under the applicable industry test procedures is generally a curtain wall requirement on larger projects; smaller storefront scopes more commonly require a field water test on an installed area instead. Which applies, and to what standard, is set by Part 1 of the project specification, so check it there rather than assuming.

Two implications for the drawings:

• Shop drawings are produced for the mock-up specimens themselves, ahead of the full building set — an additional, earlier submission that has to be programmed
• Mock-up results feed back into the package. Where a mock-up identifies a water path or a movement issue, the full building shop drawings are developed incorporating those results, which is a revision cycle that must be in the programme rather than a surprise

The Submittal and Approval Cycle for Facade Packages

The mechanics are the same as any other package — submittal register, transmittal, review, comment response, resubmission, release — and are covered in full in our guide to shop drawings in construction. Four things are specific to facade.

The package is split. Anchors and embeds go first, driven by the structural pour programme. Mock-up drawings follow. The full building set follows that. Each has its own review period.

Three reviewers, not one. The architect reviews design and performance. The structural engineer of record reviews the delegated calculations against the specified criteria. Finish samples run a separate physical approval loop. A package that clears the architect can still be held by either of the other two.

Delegated calculations must be signed and sealed by an engineer holding the appropriate professional registration for the jurisdiction — the Saudi Council of Engineers in Saudi Arabia, or the relevant emirate-level engineering registration in the UAE. Registration requirements and the scope of what must be sealed differ between jurisdictions and are periodically revised; confirm the current position with the authority and with the client’s consultant before assuming an engineer’s credentials will be accepted.

Authority review can sit on top. Fire-related aspects of the envelope — facade material classification, perimeter firestopping, compartmentation at the slab edge — typically require civil defence review in addition to consultant approval, with its own timeline. Mark those items on the submittal register at kick-off and give them longer lead times than consultant-only items.

Documents should be issued and revised through the project’s common data environment, so that the submittal log and the drawing status never disagree.

Eight Reasons Curtain Wall Packages Get Rejected

Documented rejection reasons across published glazing submittal guidance and facade drafting practice cluster into eight patterns. Most are avoidable at the internal QA step.

Producing Curtain Wall Shop Drawings From BIM at LOD 400

A facade package extracted from a coordinated model starts ahead, because the reconciliation with the structure has already been done and every view is generated from the same geometry.

The model has to be developed far enough to support it. LOD 400 is the level that carries manufacturer-specific components, connection detail, assembly information and tolerances — which is what a facade fabricator needs. An LOD 300 model carries accurate geometry but not the brackets, splices and fixings, so a package extracted from it will be incomplete regardless of how well it is drafted.

A workable facade model-to-drawing workflow has four parts:

• Federate against the structural model and run clash detection first. On facade the critical checks are slab edge position, embed clash with reinforcement, and bracket clash with perimeter services and firestopping
• Develop the facade to LOD 400 — brackets, splices, fixings, gaskets and thermal breaks modelled, with product data attached
• Add 2D detail where modelling is not worth it — sealant profiles, membrane laps, gasket sections and standard notes as detail components over model views
• Drive schedules from the model — the glass schedule, extrusion cut lists and bill of materials come from the same source as the geometry, so a change to a panel updates both

Where the geometry is complex or the as-built frame has drifted, a laser scan-to-BIM survey of the anchor line gives a measured basis for reconciliation rather than a spot-checked one.

Pre-Submission QA Checklist

Run this before every facade submittal. It is the cheapest intervention available on the whole cycle.

1. The source architectural and structural drawing revisions are stated on the sheet and confirmed current in the CDE.
2. Every elevation opening reconciles with the architectural set.
3. Design wind pressures on the general notes match the structural documents.
4. Every bracket type on the drawings appears in the delegated calculations, and vice versa.
5. The calculations are signed and sealed by an engineer registered for the jurisdiction.
6. Every expansion gap is dimensioned and an installation reference temperature is stated.
7. Fixed and sliding anchors are distinguished unambiguously.
8. Fixing schedules state substrate, type, size, centres, embedment and edge distance.
9. The air and water barrier line is continuous and traceable through every section.
10. Every glazing type carries full makeup, heat treatment and assembly performance values from the fabricator’s tool.
11. Sealant compatibility and adhesion test results are included.
12. Perimeter firestopping and its interface with the spandrel and back pan are drawn.
13. Panel or member joint widths are shown as a range, not a single nominal figure.
14. The anchor line as-built survey has been reconciled before release to fabrication.
15. Every deviation is clouded, listed and explained in the transmittal.
16. Every comment from the previous revision has a written response.

Frequently Asked Questions

What is a curtain wall shop drawing?

A curtain wall shop drawing is a fabrication-level and installation-level drawing set prepared by the facade specialist contractor or its detailing consultant, showing exactly how a specific curtain wall system will be manufactured, anchored to the structure and installed. It is submitted for review before any extrusion, glass or anchor is ordered or cut.

What is the difference between architectural facade drawings and curtain wall shop drawings?

Architectural facade drawings establish design intent — the module, sightlines and performance criteria the envelope must achieve. Curtain wall shop drawings show how one specific system, using a named profile series, a named glass makeup and named anchors, delivers that intent on the actual structure with its actual tolerances. They have different authors, different purposes and different contractual status.

What does a complete curtain wall shop drawing package contain?

Eleven categories: cover sheet and index, general notes and legend, key plans, elevations keyed to the architectural grid, vertical and horizontal sections, head, jamb and sill details, anchor and embed layouts, corner and transition details, glass and panel schedules, extrusion and bill of materials, and installation sequence sheets. Package size varies from around a dozen sheets for a simple tender-stage set to several hundred for a full approval package on a complex tower.

What is delegated design in curtain wall work?

The architect specifies performance — wind pressures, deflection limits and movement allowances — and the facade contractor’s own engineer designs the system to meet it, submitting signed and sealed structural calculations. The engineer of record reviews those calculations for conformance with the specified criteria rather than re-performing the analysis.

How many review cycles are normal on a curtain wall submittal?

Two review cycles are commonly cited as normal for curtain wall in published glazing submittal guidance, because three parties review different things: the architect reviews design and performance, the structural engineer reviews the delegated calculations, and finish samples run a separate physical approval loop. Actual cycles depend on the completeness of the first submission and on how far the package was coordinated before it went out.

How long are curtain wall fabrication lead times after approval?

Published trade guidance commonly puts glazing fabrication lead times at eight to sixteen weeks after approval, and longer for custom finishes or oversized lites. These figures are indicative and move with market conditions, mill capacity and finish type, so confirm the actual lead time with your supplier for the actual project rather than programming against a general figure.

Why does thermal movement matter so much for curtain wall in Saudi Arabia and the UAE?

Aluminium expands and contracts with temperature — the coefficient of linear thermal expansion for structural aluminium alloys is commonly taken as approximately 23 × 10⁻⁶ per °C, subject to confirmation against the specific alloy and applicable code. In Gulf conditions a dark-finished mullion on a west elevation experiences a surface temperature range considerably wider than ambient, because solar gain adds to it. The drawings must therefore dimension every splice gap, state an installation reference temperature, distinguish fixed from sliding anchors, and size sealant joints against the calculated movement.

When are embed and bracket drawings submitted?

Before the full shop drawing package, and before the relevant floors are poured. Established facade engineering practice is to issue embed and bracket layout drawings as a separate earlier deliverable, typically a few sheets per floor, so that connectors are cast into the concrete frame or fixed to the steel frame at the correct positions. Missing that window generally forces post-fixed anchors, which must be re-engineered and re-approved.

Do curtain wall shop drawings need authority approval as well as consultant approval?

Often yes. Fire-related aspects of the envelope — facade material classification, perimeter firestopping at the slab edge and compartmentation — typically require civil defence review in addition to consultant approval, with its own timeline. Requirements vary by jurisdiction and are periodically revised, so confirm the current position with the relevant authority before setting the submittal programme.

What LOD is needed to produce curtain wall shop drawings from a BIM model?

LOD 400. That level carries manufacturer-specific components, connection detail, assembly information and tolerances — the brackets, splices, fixings and thermal breaks a facade fabricator needs. LOD 300 carries accurate geometry but not that connection content, so a package extracted from an LOD 300 model will be incomplete.

Conclusion

Curtain wall is the package where drawing quality and commercial outcome are most tightly coupled. The glass and aluminium are ordered off these sheets, the structural frame is poured around the embeds on these sheets, and the facade either fits the building it was drawn for or it does not.

The technical content — makeup, anchorage, thermal movement, weatherproofing — is what a reviewer checks. But the discipline around it is what determines how many cycles it takes: stating which revision you drew against, dimensioning movement rather than assuming it, reconciling the anchor line against a real survey, and clouding every deviation so that approval is given knowingly. On Gulf projects, where a facade sees a temperature range most detailing guidance was never written for, that discipline is not administration. It is the difference between a facade package that supports the programme and one that becomes it.