Curved, Sloped, and Faceted Unitized Curtain Wall: RFQ Questions to Ask

Curved Panels and Curved Glass

“Curved” should be defined more precisely than a plan note or marketing description. The curve may apply to the glass, framing, panel outline, building line, or more than one element. It may occur in plan, elevation, or multiple directions.

Geometry questions

• Is the curve in plan, elevation, or both?
• What radius or curve definition controls, where relevant?
• Which coordinates, datum, origin, and orientation should be used?
• Are the panels constant-radius, variable-radius, faceted approximations, or another configuration?
• What panel width, height, edge, chord, arc, offset, and connection references are required by the project documents?
• Which tolerances and revision fields apply?
• Which panel marks and quantities identify the curved units?

Do not prescribe a universal radius, coordinate system, tolerance, or fabrication method. Those fields must come from controlled project information and professional review.

Glass, frame, and seal questions

• glass type and make-up;
• whether the glass, framing, infill, or panel outline is curved;
• thickness, coatings, interlayers, spacers, and gas assumptions where relevant;
• edge, joint, visual, and sample requirements;
• aluminum profile, reinforcement, and connection basis;
• gasket and seal path, closure, cover, and drainage assumptions;
• compatibility information; and
• factory-glazing, sealing, inspection, and replacement boundaries.

A generic “curved glass” label does not establish feasibility, performance, or quotation inclusion. Request the configuration-specific basis and identify unresolved items.

Yuanda’s public unitized-system page presents examples of single-direction and bidirectional arc forms in its own system context. This supports questions about how a supplier defines proposed geometry; it does not prove that every supplier can fabricate or install the same form, or that a particular quote includes it.

Sloped Panels and Non-Vertical Conditions

A sloped panel should be described through its plane, direction, datum, orientation, dimensions, interfaces, and handling assumptions. “Sloped facade” alone may not identify whether the slope is in plan, elevation, or a three-dimensional model.

Slope and datum questions

• Is the slope defined in plan, elevation, or a project-controlled three-dimensional coordinate system?
• What angle, slope direction, datum, origin, and orientation control?
• What are the panel dimensions, edge conditions, offsets, and tolerances?
• How are panel marks, quantities, batches, and installation orientation shown?
• Which connections, anchors, brackets, closures, covers, gaskets, and seals apply?
• Which geometry-specific interfaces require review?

The quotation should identify the controlling project information rather than assume a standard slope basis.

Drainage and handling questions

For a sloped condition, ask the responsible project professionals to review drainage and water-management assumptions; glazing-plane and seal interfaces; edge closures and cover transitions; substrate, anchors, brackets, and adjustment provisions; access for inspection and maintenance; packaging and transport orientation; and lifting, storage, and installation conditions.

Do not give drainage, structural, fire, waterproofing, or performance approval from a generic slope description. Do not infer a fixed cost, delivery period, damage result, or installation result from the slope alone.

Faceted, Triangulated, Trapezoidal, Parallelogram, Warped, and Non-Orthogonal Modules

Faceted and non-orthogonal panels should not be grouped into one generic “custom” quantity if their geometry, orientation, edges, connections, or materials differ.

For each special panel, record geometry type and panel orientation; coordinates, angles, edge lengths, radii, or slopes where relevant; panel width, height, edge dimensions, and offsets; adjacent-panel relationships; glass/infill, aluminum, seal, closure, cover, anchor, and connection basis; panel marks, quantities, and locations; and drawing/model/detail revision.

Yuanda’s official page publicly describes triangular, trapezoidal/parallelogram, curved, hyperboloid, and deformed-elevation forms in its own system presentation. This is a supplier-specific public description and cannot establish universal fabrication capability, price, performance, or installation outcome.

Special-panel status questions

• Which panels are typical, repeated, mirrored, unique, or special-condition?
• Which panels are included in the base schedule and which remain allowances or subject to confirmation?
• Are adjacent panels planar, curved, faceted, or another non-orthogonal form?
• Which edge conditions, closures, covers, gaskets, seals, anchors, and connections are included?
• What orientation, packaging, lifting, storage, and site-access assumptions apply?

Geometry Data, Coordinates, Angles, Radii, Slopes, Dimensions, and Tolerances

The RFQ should use the project’s controlled drawing or model basis. Depending on the project, relevant fields may include:

Do not prescribe a universal coordinate system, radius limit, angle range, or allowable deviation. Values should come from project documents, system data, and qualified design/professional review.

Glass, Aluminum, Gaskets, Seals, Closures, Covers, Anchors, and Connections

Special geometry can make material and interface assumptions more important to the quotation basis. Ask for a configuration-specific response rather than relying on a broad product name.

YKK AP’s public guide describes system-option, mullion-depth, face-cover, movement, water-management, and engineering-support categories in its own product context. Use these as prompts for the proposed basis, not as universal requirements or capability evidence.

For non-orthogonal modules, also ask how panel orientation and connection direction are shown, which anchors and adjustment provisions are included, how adjacent edges and joints connect, and who reviews the connection, movement, water, fire, and installation interfaces. These are quotation questions; specialist decisions require qualified project-professional review.

Shop Drawings, BIM, Mockups, and Testing Questions

Geometry-specific drawings and BIM

Ask whether the quotation includes special-geometry plans, elevations, sections, and enlarged details; panel and fabrication drawings with marks, dimensions, orientation, and edge data; BIM geometry, coordinates, model exchange, and coordination; material schedules and interface details; calculations or technical submissions assigned to the supplier; revisions after project/design-team review; samples and mockup drawings; and final geometry or handover records.

The scope should identify the responsible party and review path. A BIM model or shop drawing is not automatically design approval.

Laboratory and field mockups

• Which geometry and interfaces are representative?
• Which glass, framing, seals, closures, connections, and openings are included?
• What construction sequence, tolerances, and installation conditions are represented?
• Who designs, fabricates, constructs, observes, tests, evaluates, and documents the mockup?
• What changes or retesting may be required if the configuration is revised?

ASTM E2099-23 covers pre-construction laboratory mockup design, construction, observation, testing, evaluation, documentation, and coordination. ASTM E3223/E3223M-20 covers field-constructed exterior-wall mockups and includes constructability, construction sequence, interference, tolerances, component/assembly performance, and system intersections. These references support project-role and interface questions; they do not establish a universal test list or project acceptance.

Movement-related test-method questions

FGIA/AAMA 501.4-18 and FGIA/AAMA 501.7-17 describe static test methods for specified horizontal or vertical interstory displacement. Use these as test-method references only.

• Which movement or test requirement applies to the special geometry?
• Is the specimen representative of the proposed glass, framing, seals, closures, and connections?
• What test method, agency, witnessing, report, and retesting basis applies?
• Which design, facade, glass, fire, and testing professionals review the result?

Do not state that a test method, mockup, or generic product page proves code compliance, project performance, or acceptance.

Factory Assembly, Packaging, Transport, Lifting, Storage, and Site Installation Questions

Keep these questions tied to special geometry rather than turning them into a general logistics or installation guide. Ask whether special panels are assembled, glazed, sealed, inspected, labeled, stored, reworked, and released at the factory. Request a clear basis for panel identification, orientation, traceability, and release records.

• How are curved, sloped, faceted, or non-orthogonal units protected?
• What labels identify panel orientation and installation location?
• Which crates, racks, frames, or supports are assumed?
• What transport orientation, loading, unloading, lifting, and access constraints apply?
• What storage orientation, weather protection, and site-security conditions apply?
• Who handles damage inspection, replacement, and re-delivery?
• Does the installation scope address panel orientation, floor release, staging, site adjustment, inspection, records, and handover?

Yuanda publicly describes factory assembly and integral hanging installation. Hydro publicly describes off-site unitized-panel assembly and installation at the building structure. These are company or system descriptions, not universal inclusions or installation guarantees.

Geometry and Panel Schedule Checklist

This checklist organizes special-geometry quotation inputs; it is not a design, code, testing, installation, or acceptance approval checklist.

Special-Condition Register

Use a register to connect each special zone to its geometry, panel, material, document, responsibility, status, and next action.

Suggested workflow statuses include Controlled, To be confirmed, Professional review, Responsibility to assign, Open, Evidence received, and Carry forward. These are workflow fields, not fabrication approval, technical compliance, or supplier judgments.

Special-Geometry RFQ Clarification Questions to Ask

1. Which controlled drawing, model, detail, and revision define the special-geometry zone?
2. Is the condition curved, sloped, faceted, triangulated, trapezoidal, parallelogram, warped, or another non-orthogonal form?
3. What coordinates, angles, radii, slopes, orientations, dimensions, and tolerances control the quotation basis?
4. Which panels are typical, repeated, mirrored, unique, or special-condition panels?
5. How are panel marks, quantities, locations, and installation batches identified?
6. What glass, aluminum, gaskets, seals, closures, covers, anchors, and connections are included or subject to confirmation?
7. Which drawings, shop drawings, BIM, calculations, samples, mockups, and tests apply?
8. Which factory assembly, labeling, packaging, transport, lifting, storage, and site-installation assumptions apply?
9. What geometry-specific interfaces require coordination, and who is responsible for each?
10. Which cost, programme, testing, logistics, or installation effects remain To be confirmed?
11. What configuration-specific evidence is needed before the supplier can state its proposed basis?
12. Which design, facade, glass, fire, testing, logistics, installation, contract, or procurement professional should review the open item?