Facade materials cannot be compared fairly as isolated sheets. A terracotta rainscreen, stone veneer, metal cladding, glazed curtain wall and ceramic facing may perform different enclosure roles. Compare complete, defined wall systems against the same project requirements and evidence scope.
Define the wall typology before comparing materials
A rainscreen is generally discussed as an outer cladding with a cavity and separate enclosure layers; curtain wall commonly describes a non-loadbearing exterior wall assembly; veneer describes a facing attached to backing. Project documents must define the actual construction rather than using these terms interchangeably.
Draw a section for every candidate from exterior face to interior finish. Name cladding, joints, cavity, drainage, air and water controls, insulation, fire barriers, supports, anchors, substrate and interior layers. Only then can teams compare systems at a common boundary.
Also define which layers are included in each supplier’s scope and which remain by others. Two proposals can appear equivalent while one omits critical membranes, brackets, engineering or access. Make those boundaries visible before scoring.
Compare structure and attachment on equal terms
Design actions
Use the same project wind, seismic, permanent, impact and maintenance inputs where applicable.
Load path
Trace facing, clips or frames, rails, brackets, fasteners and anchors to the verified substrate.
Movement
Compare how each complete system accommodates building, thermal and construction movements.
Evidence
Match calculations and tests to actual materials, geometry, connections and boundary conditions.
Do not compare material density alone or assume that lighter always means less support. Module, thickness, framing, anchors, deflection criteria, replacement strategy and substrate can change the complete installed solution. Record exclusions and design responsibilities.
Evaluate air and water control as an assembly
Map rain entry, drainage, pressure moderation where relevant, flashings, joints, seals, transitions and drying. Identify the primary air and water control layers. An open-jointed terracotta rainscreen and a sealed glazed assembly address water differently and should not be scored through the same isolated material property.
Compare project-specific mock-ups, tests or assessments with their specimens, pressures, interfaces and limits. Include corners, openings, parapets, bases and penetrations. A cladding marketed as waterproof or self-cleaning does not replace complete wall design.
Compare fire and thermal scope precisely
For fire, identify the exact material, component or assembly covered by each classification or test, including insulation, membranes, cavities, barriers, supports and joints. Do not transfer a facing result to the complete wall or between different constructions.
For thermal review, compare whole-wall models using the same climate, geometry, insulation targets, thermal bridges, frames, anchors and interior conditions. Conductivity or insulation claims for one component cannot determine complete enclosure performance. Keep condensation analysis within the project-specific wall study.
Assess appearance and variation with physical samples
Compare colour mechanism, gloss, texture, module, joints, reflectance and expected variation through production-intent samples and representative mock-ups. Natural stone, fired clay, coated metal, glass and other ceramics each need product-specific acceptance rules rather than stereotypes.
Review daylight, wet conditions, night lighting, adjacent materials and multiple viewing distances. Define repair and replacement appearance as well as initial approval. Do not claim that any category never fades, corrodes, weathers, stains or varies.
Compare maintenance, cost and programme
Compare access, inspection points, cleaning restrictions, joint or seal renewal, damage assessment, component replacement, spare strategy and disruption. Use current supplier information and the building’s actual access plan. “Low maintenance” requires a defined scope and period.
Consider how concealed components are inspected and how replacement affects adjacent layers. Record expected responsibilities at handover. Avoid assigning a universal life to any material; service outcomes depend on product, environment, design, workmanship and maintenance.
Cost, programme and environmental evidence
Build a common cost boundary covering design, prototypes, testing, materials, subframe, anchors, special pieces, finishes, packaging, transport, installation, access, inspections, maintenance, replacement and end-of-service assumptions. A unit price alone can favour an incomplete scope.
For programme, compare design release, engineering, procurement, tooling, samples, testing, approvals, production, logistics and installation sequence. For environmental review, use current product-specific declarations or project methods with stated boundaries rather than broad natural, recyclable or resource claims.
State the study period, discount or escalation assumptions where used, replacement events, access costs and uncertainty. The objective is not a false single-number certainty, but a transparent view of which scope and assumptions drive the commercial result.
Issue a transparent decision matrix
Score only criteria defined by the project and attach the source, revision, configuration and confidence to every entry. Mark missing information instead of converting it into a weak or strong rating. Sensitivity testing can show which assumptions change the decision.
Review the current terracotta rainscreen range and relevant project references as one option, then verify applicability. Preserve the comparison matrix, evidence, approvals and change history through design development.