A “new” curtain-wall material is not a specification and novelty is not evidence of suitability. Start by identifying the exact product and every layer, fixing and interface in the proposed wall. Then map each project requirement to a current document, calculation, test, mock-up, inspection or maintenance provision with a clear scope.
This guide uses three material families retained from the 2020 source—mechanically retained terracotta, stainless-steel composite panels and building-integrated photovoltaic glazing—as examples. It does not rank them, predict a trend or claim that an image proves the material used.
1. Turn a material name into a verifiable identity
Face product
Record manufacturer, legal/product name, factory, family, composition and core/laminate where relevant, dimensions and tolerances, finish/coating, batch or lot, edge treatment and fabrication route.
Retention and support
Identify clips, kerfs, inserts, rails, brackets, anchors, fasteners, gaskets, isolators, adhesives or sealants, secondary steel and their material grades, coatings, geometry and adjustment.
Backing wall and interfaces
Define structure/substrate, sheathing, air/water layer, insulation, cavity, flashings, openings, parapets, movement joints, fire barriers and perimeter fire-stopping.
Exposure and service
State climate, height and orientation, wind/seismic actions, temperature and moisture, coastal/chemical/UV exposure, impact, access, cleaning, inspection, replacement and intended service conditions.
2. Apply the same evidence discipline to different material families
Mechanically retained terracotta
Define the fired-clay body, hollow/solid profile, finish, dimensions, orientation, edge and clip/rail interface. Unit strength, absorption, freeze/thaw or reaction-to-fire data—where required—must match the exact product and do not replace wind-load, water-management, movement, fire-cavity and attachment checks for the wall.
Stainless-steel composite panel
The generic name is incomplete. Identify stainless alloy/finish and skin thickness, core or backing, bonding route, edges, stiffeners and attachment. Assess core/fire behaviour, bond durability, oil-canning/flatness, corrosion and galvanic interfaces, moisture at cut edges, movement, replacement and finish maintenance.
Photovoltaic facade glazing
Building-integrated photovoltaic glazing is both envelope construction and an electrical generating assembly. Define glass make-up, cells, interlayers/encapsulants, coatings, framing, seals, wiring, connectors, junction boxes and access. Coordinate structural glass, electrical/fire safety, weathering, shading, heat, drainage, isolation, shutdown and replacement.
Any unfamiliar or altered product
Ask what is genuinely different: composition, factory, dimensions, coating, core, attachment, production process or intended use. Require evidence for the changed item and its interfaces; similarity in appearance or marketing name is not technical equivalence.
3. Build a requirement-to-evidence matrix
| Requirement | Project-specific evidence | Do not infer from |
|---|---|---|
| Identity and manufacture | Current data/declaration, drawings, composition, factory and quality-control scope, dimensions/tolerances, finish, traceability and intended use. | Brand name, colour sample, catalogue photo or a certificate for another factory/product. |
| Structural and movement | Applicable actions and combinations, engineer’s calculations, component/connection evidence, full-size or representative tests where specified, deflection/movement and substrate/anchor checks. | Face-unit strength, low weight, a software screenshot or a precedent image. |
| Fire | Code strategy separating material reaction, cavity/insulation/barriers, perimeter interfaces and exterior-wall assembly requirements; exact reports/classifications and installation scope. | “Non-combustible,” “fireproof” or a face-material result extended to adhesives, core, subframe and wall. |
| Water and air | Drainage and pressure-equalisation concept, membranes/flashings/openings/joints, representative laboratory mock-up and field checks to the specified standards and acceptance criteria. | Low absorption of one component or an intact-looking elevation. |
| Thermal and moisture | Whole-wall calculation/model including insulation continuity, rails/brackets/anchors, linear/point bridges, glazing/frame, condensation risk, movement and climate/interior conditions. | Hollow panel geometry, a material conductivity value or a generic “energy-saving” statement. |
| Durability and compatibility | Exposure-specific corrosion/coating, freeze/thaw or weathering data as relevant; sealant/adhesive/gasket/cleaner compatibility; differential movement; edge and drainage details; ageing or project trials. | One accelerated test, generic long-life claim or separate component warranties. |
| Environmental and health | Current product/factory-specific EPD, HPD or other required declaration with programme operator, date, scope, declared unit, lifecycle stages and limitations. | “Natural,” “green,” “non-polluting,” recyclable appearance or an unrelated certificate. |
| Maintainability | Access, inspection/cleaning method, spare strategy, demounting/replacement sequence, electrical isolation where relevant, repair limits, records and responsible parties. | Easy-installation claims or an assumption that face units can be changed without opening interfaces. |
Create a project code-and-standards register rather than copying a universal list. For every calculation or report, record the exact standard and edition, laboratory/author, date, specimen and build-up, size and support conditions, deviations, result, acceptance criterion and relationship to the proposed construction. A pass applies only within its documented scope.
4. Resolve compatibility and interfaces before the mock-up
Review chemical compatibility among coatings, sealants, gaskets, membranes, adhesives, cleaners and adjacent materials. Review galvanic and runoff staining risks between dissimilar metals; corrosion at cut edges, fasteners and concealed wet zones; and differential thermal, moisture and structural movement. Define isolation, drainage, ventilation, tolerances and replaceable interfaces on coordinated drawings.
Fire and water strategies must remain continuous through corners, parapets, bases, openings, transitions and movement joints. For photovoltaic facade glazing, add cable routing, penetrations, earthing/bonding, isolation, arc/fire provisions, drainage around electrical parts, maintenance access and emergency procedures under the responsible electrical and fire design. An energy-yield estimate must use the actual module, orientation, shading, temperature and system losses; a reflective appearance is not evidence of generation.
5. Use staged samples, mock-ups and inspections
Selection and control samples
Approve identity, colour, texture, gloss, pattern, visible variation and reference range. Record source, finish, date and limitations; a small sample does not approve large-panel flatness, joints or weathering.
Fabrication prototype
Review full-size units, edges, cut-outs, corners, fixings, tolerances and handling. Include difficult transitions and replacement access rather than only an ideal centre-bay panel.
Performance mock-up
Build representative structure, supports, face units, joints, air/water layers, insulation, fire interfaces and openings. The project specification defines sequence, standards, pressures/actions, acceptance, observation and remedial/retest rules.
Production and site QA
Link incoming materials and batches to inspections, dimensions/finish, fixings, substrate, installation records, field checks, nonconformances and accepted repairs. Keep concealed-work photographs and as-builts.
6. Control substitutions and hand over maintainable evidence
Require a change register that names the proposed and approved items, reason, drawings/specification affected, technical comparison, new risks, evidence reviewed, sample/mock-up impact, cost/programme impact and written approvals. “Equal,” “similar” or “same appearance” is not a disposition. Do not permit procurement or installation until responsibility for the revised complete assembly is clear.
- approved product/system schedule, manufacturers, factories, batch/lot and final as-built drawings;
- code/standards register, calculations, reports/classifications and their exact scope;
- approved samples, mock-up records, inspections, field checks and nonconformance dispositions;
- component compatibility, corrosion, movement, fire, water, thermal/moisture and electrical coordination;
- cleaning and maintenance methods, access, inspection triggers, repair limits and replacement sequence;
- spares with product/finish/batch identification and protected storage requirements;
- warranties and exclusions mapped to named parties without treating them as system certification; and
- change register, current contacts and owner/facility-team training.
For current fired-clay product context, review Terracotta Rainscreen and dated files in Catalogues & Downloads. Request current documents for the exact product, factory, finish, fixing concept and project use; neither this guide nor a catalogue image is an approval.
Request product-specific evidence for a facade brief
Send the project location, wall build-up, elevations/details, product and finish brief, support concept, exposures, applicable requirements, evidence schedule, mock-up/testing plan and programme. LOPO can identify available terracotta information; the qualified project team remains responsible for material selection, interfaces, system design, compliance and acceptance.