Evidence of suitability is the NCC’s framework for answering a straightforward question: how do you prove that a building product or system will actually do what you claim it will do? For facade products, this means demonstrating that the cladding meets the fire, structural, and weatherproofing requirements set out in the code. Get the evidence right, and certification moves smoothly. Get it wrong — or leave gaps — and the project stalls while everyone works backwards to fill them.
This article explains how the evidence of suitability provisions work under NCC 2022, what documents certifiers need to see for facade products, and how the Deemed-to-Satisfy and Performance Solution pathways differ in practice.
What is evidence of suitability under NCC 2022?
Part A5 of NCC 2022 sets out the evidence of suitability requirements. It applies across the board — structure, fire, waterproofing, energy, accessibility — but for facade products, the fire and weatherproofing evidence is where most of the attention falls.
The NCC does not prescribe a single way to demonstrate suitability. Instead, it lists several acceptable forms of evidence, including:
- A report issued by a NATA-accredited testing laboratory confirming the product has been tested to the relevant Australian Standard and meets the specified requirements.
- A certificate or report from a product certification body accredited by JAS-ANZ, such as a CodeMark certificate.
- A certificate issued by a professional engineer or other suitably qualified person, based on their assessment of the product’s fitness for purpose.
- A report from an Accredited Testing Laboratory published in the Scientific or Technical Literature.
In practice, the most common and straightforward evidence for facade products is NATA-accredited test reports. These are specific, verifiable, and widely accepted by certifiers across all states and territories.
What do certifiers actually need to see?
A certifier assessing facade cladding on a Type A or B building is looking for evidence that addresses three core requirements.
Non-combustibility. Under the Deemed-to-Satisfy provisions of C2D10, external wall cladding materials on multi-storey buildings generally need to be non-combustible. The evidence for this is an AS 1530.1 test report from a NATA-accredited laboratory. The report must be for the specific product being installed, not a generic test on a similar material.
For aluminium facade products, this is typically straightforward. Solid aluminium and extruded aluminium are inherently non-combustible. But the certifier still needs to see the report, because the NCC requires evidence, not assumptions. A product data sheet stating “non-combustible” without a test report reference is not sufficient.
Weather performance. AS/NZS 4284 testing demonstrates the facade system’s resistance to water penetration, air infiltration, and structural performance under wind pressure. The certifier needs to see a test report showing the system has been tested to pressures relevant to the building. For many metropolitan Australian projects, plus or minus 1500Pa at serviceability limit state is a common benchmark, but the actual requirement is project-specific and driven by the wind load analysis.
Structural adequacy. The certifier needs evidence that the facade system can resist the wind loads specific to the project. This typically comes in two parts: the supplier’s product test data (what the system is capable of) and a project-specific facade engineering report (what the building requires and how the system is fixed to achieve it). The supplier provides the first; a facade engineer provides the second.
Beyond these three, certifiers may also request coating certifications, installation methodology, and maintenance documentation depending on the project and the building class.
How does the DTS pathway work for facades?
The Deemed-to-Satisfy pathway is the most common compliance route for facade cladding. It works by demonstrating that the product and installation meet the prescriptive requirements set out in the NCC, without needing to demonstrate performance through alternative analysis.
For external walls, the key DTS provision is C2D10, which requires materials to be non-combustible. C2D10(5) lists materials that are deemed non-combustible without testing — concrete, masonry, stone, terracotta, ceramics, and metals commonly used in building. Aluminium falls within this list as a common construction metal, but certifiers will still expect to see a test report for the specific product, particularly for products with coatings or composite elements.
The DTS pathway is appealing because it is well understood, widely accepted, and does not require fire engineering input beyond the standard documentation. If the product is non-combustible to AS 1530.1, tested to AS/NZS 4284, and supported by a facade engineering report for the project, the DTS case is clear.
The limitation of DTS is that it does not accommodate products that fall outside the prescriptive requirements. A cladding material that is not non-combustible cannot use the DTS pathway for external walls on Type A and B construction, regardless of how it performs in other respects.
When is a Performance Solution required?
A Performance Solution is required when the proposed design does not — or cannot — comply with the Deemed-to-Satisfy provisions. For facade cladding, this typically arises in one of three situations:
The cladding material is not non-combustible. Composite panels with polymer cores, timber cladding, and some fibre cement products may not pass AS 1530.1. To use these on buildings where C2D10 requires non-combustibility, a Performance Solution is needed to demonstrate that the building as a whole still meets the relevant Performance Requirements for fire safety.
The facade system incorporates combustible components. Even when the face material is non-combustible, the system may include combustible elements — cavity barriers, thermal breaks, sealants — that take it outside a clean DTS compliance position. A Performance Solution may be used to demonstrate that these components do not compromise the building’s overall fire performance.
The design departs from prescriptive requirements. Non-standard configurations, unusual geometries, or facade systems not directly addressed by the DTS provisions may require a Performance Solution to demonstrate compliance through analysis rather than prescription.
A Performance Solution for a facade typically involves a fire engineer who assesses the system against the NCC’s Performance Requirements and prepares a report documenting their analysis, methodology, and conclusions. The certifier then reviews this report as part of the evidence of suitability package.
Performance Solutions are more expensive and time-consuming than DTS compliance. They require specialist input, take longer to prepare, and may face greater scrutiny during certification. For this reason, selecting non-combustible facade products at the specification stage — where the DTS pathway is available — is the simplest way to avoid the need for a Performance Solution on the facade.
What are the common evidence gaps?
Several documentation gaps appear repeatedly on projects, and almost all of them are avoidable with early attention.
Test reports that do not name the product. A test report for “3mm aluminium sheet” is not evidence of suitability for a named facade product. Certifiers need to see the product identified on the report.
Reports from non-NATA laboratories. The NCC’s evidence of suitability provisions specifically reference NATA-accredited laboratories. Reports from overseas labs or non-accredited facilities may not be accepted, or may require additional supporting evidence.
No compliance statement linking evidence to NCC clauses. Test reports are evidence. The compliance statement is the argument that connects the evidence to the specific NCC requirements. Without it, the certifier has raw data but no structured case for approval.
Missing facade engineering report. Product test data shows capability. The facade engineering report shows application — that the product, as installed on this building, will resist the loads it needs to resist. One does not substitute for the other.
Assuming the DTS pathway when the system includes combustible components. If any part of the facade assembly is combustible, the clean DTS position may not hold, and the evidence package needs to address that — either through the NCC’s minor combustible concessions or through a Performance Solution.
How does Valmond & Gibson support the evidence of suitability process?
Valmond & Gibson provides the product-side documentation that forms a core part of the evidence package. For interloQ, this includes an AS 1530.1 non-combustibility report from CSIRO (report FNC12595, NATA accreditation 165) and an AS/NZS 4284 weather performance report at plus or minus 1500Pa SLS (report 2022-031-S1, NATA accreditation 2371). For element13, the package extends to AS 1530.1 (FNC12545), AS 1530.3 (FNE12552), AS/NZS 4284 (2022-031-S2), AAMA 2605 coating certification, and impact resistance testing.
Each report is issued by a NATA-accredited laboratory and can be cited directly in compliance statements and evidence of suitability submissions. If you need documentation for a current project, our team can provide the compliance packs and walk you through what is available.
Need evidence of suitability documentation for a facade project? Talk to our team for compliance packs and specification support.
Related Reading
- Facade Documentation: What Certifiers Actually Need to See
- CodeMark Certification: What It Means for Facade Products
- Performance Solutions vs Deemed-to-Satisfy
- How to Write a Facade Specification
Last updated: 4 April 2026