A facade mock-up is a full-scale sample of the facade assembly, built and tested before the main facade is manufactured and installed. On medium and large projects, it is one of the most effective risk-reduction steps available - and on curtain wall projects, it is often a contractual requirement.
There are two types, and they serve different purposes. Understanding which applies - and when neither is necessary - helps avoid both unnecessary cost and avoidable risk.
What is the difference between a visual mock-up and a performance mock-up?
A visual mock-up is a sample panel or small section of facade assembled on site. Its purpose is to confirm appearance: colour, texture, joint widths, shadow lines, and how the facade reads at full scale. It is relatively inexpensive - typically a few panels on a temporary frame - and it gives the architect, builder, and client a physical reference point before the full facade is manufactured.
A performance mock-up is a laboratory-tested assembly. A representative section of the facade - typically two bays by two storeys for curtain wall - is assembled in a NATA-accredited testing facility and subjected to controlled tests to AS/NZS 4284 for water penetration, air infiltration, and structural adequacy. The mock-up proves that the as-built assembly performs to specification, not just the as-designed one.
When is a performance mock-up typically required?
Performance mock-up testing is most commonly required on curtain wall projects. The 165CW unitised curtain wall system, for example, involves complex framing, gasket interfaces, structural silicone joints, and movement accommodation between panels. The facade engineer and certifier will often require a project-specific mock-up to verify that the particular configuration performs as a system under the design loads.
Large commercial projects where the facade specification explicitly calls for AS/NZS 4284 testing are the other common trigger. This is particularly likely where the building is in a high wind region, where the facade includes non-standard details, or where the certifier wants physical confirmation that the design intent translates to the installed product.
The cost of a performance mock-up typically ranges from $30,000 to $80,000 or more, depending on the size and complexity of the test specimen. Lead time is generally four to eight weeks for manufacture, assembly, and the testing program.
When is a mock-up usually not required?
Standard rainscreen cladding systems - interloQ interlocking panels and element13 solid aluminium panels - do not typically require project-specific mock-up testing. These systems have already been tested to AS/NZS 4284 at serviceability limit state pressures of plus or minus 1,500 Pa. The system test results demonstrate the performance of the assembly as designed, and project-specific retesting is not normally necessary unless the facade engineer identifies non-standard conditions.
This is one of the practical advantages of specifying a tested system. The testing has already been done, the results are documented, and the certifier can rely on the existing test evidence rather than requiring a new mock-up for every project.
What does performance mock-up testing actually involve?
The test specimen is assembled in the laboratory exactly as it would be installed on the building - same profiles, same gaskets, same fixings, same glazing or panel types. It is sealed into a test chamber and subjected to the AS/NZS 4284 test sequence: water penetration testing under calibrated spray and increasing pressure differentials, air infiltration measurement at specified pressures, and structural load testing with positive and negative wind load cycles checking for permanent deformation or failure.
The testing program is witnessed and documented, and the results form part of the facade compliance package for the project.
Why is it worth it?
The cost of a mock-up is significant in isolation. In the context of a project where the facade might cover 5,000 or 10,000 square metres, it is modest insurance.
A performance mock-up identifies installation issues before they are repeated across the entire building. It confirms that the assembly performs under load and weather exposure, not just on paper. It gives the certifier documented evidence that the system works. And it provides a training opportunity for the installation team - the crew who build the mock-up carry that experience onto the main facade installation.
A visual mock-up is even more straightforward. Colour reads differently at full scale than on a sample chip. Joint widths that look fine on a drawing can look wrong on a wall. A visual mock-up resolves these questions with a physical reference, photographed and approved, before thousands of panels are manufactured.
What does Valmond & Gibson provide for mock-up projects?
Valmond & Gibson supports mock-up processes by providing materials, technical documentation, and guidance on system detailing. For 165CW curtain wall projects, we work with the installer and facade engineer through the mock-up process - from specimen design through to testing and any modifications that arise from the results.
For rainscreen projects using interloQ or element13, we can supply sample panels for visual mock-ups and provide the existing AS/NZS 4284 system test reports that typically satisfy the performance testing requirement without a project-specific mock-up.
One practical recommendation
Even when a performance mock-up is not contractually required, a visual mock-up is almost always worth doing. The cost of a few sample panels is trivial compared to getting colour, joint width, or overall appearance wrong across an entire building. Install it, photograph it, get sign-off, and move on with confidence.
Related Reading
- AS/NZS 4284 Facade Testing Explained: What the Weather Test Measures
- 165CW Curtain Wall System: Australian-Designed Specification Guide
- Wind Load Design for Aluminium Facade Systems
- Quality Control During Aluminium Facade Installation
Last updated: 4 April 2026