A well-written facade specification does two things: it tells the builder exactly what to procure and install, and it gives the certifier a clear path to approval. When it does both, the project moves. When it does neither — or tries to do one without the other — delays follow.
This is a practical guide for architects writing cladding specifications on projects where NCC compliance is a primary concern. It covers the standards to reference, the test evidence to require, how to structure the materials clause, and the mistakes that cause the most problems downstream.
What should a facade specification actually achieve?
The specification is the bridge between design intent and built outcome. For facade cladding, it needs to establish four things clearly:
- What the material is — alloy, thickness, form, finish.
- What compliance standard it meets — non-combustibility, weather performance, structural adequacy.
- What evidence is required — specific test reports, from accredited laboratories, referencing the correct standards.
- How substitution is handled — whether alternatives are permitted, and what they must demonstrate to be accepted.
If any of these four elements is vague or missing, the specification creates risk rather than removing it. The installer does not know what to price, the builder does not know what to approve, and the certifier does not know what to accept.
How should the materials clause be structured?
The materials clause is where most facade specifications either work or fall apart. A strong materials clause follows a consistent structure for each cladding product specified.
Name the product and supplier. Where a specific product has been selected, name it. “InterloQ interlocking rainscreen panels by Valmond & Gibson” or “element13 solid aluminium panels by Valmond & Gibson” removes ambiguity about what has been specified and what the compliance documentation will reference.
State the material properties. For aluminium facade products, this typically includes:
- Alloy grade (e.g. 6060/6063 T5 for extruded, or 3mm solid aluminium for flat panels)
- Thickness or cross-section dimensions
- Weight per square metre
- Finish type and standard (e.g. powder coat to AS 3715, PVDF to AAMA 2605, anodised to AS 1231)
Reference the compliance requirements. Rather than leaving compliance to be inferred, state it directly:
- Non-combustible when tested to AS 1530.1:1994
- Weather performance tested to AS/NZS 4284:2008
- Structural adequacy to be confirmed by facade engineer for the specific project
Require the test evidence. Specify that the supplier must provide NATA-accredited test reports for each compliance claim. This is not optional phrasing. The specification should require it.
Which standards should be referenced?
Three standards carry the most weight in facade cladding specifications for NCC compliance on Type A and B construction.
AS 1530.1:1994 — Combustibility test for materials. This is the standard the NCC references for determining whether a material is non-combustible. For external walls on multi-storey buildings, the Deemed-to-Satisfy provisions under C2D10 require non-combustible materials. AS 1530.1 is how that requirement is demonstrated.
The specification should require a test report from a NATA-accredited laboratory confirming the specific product is non-combustible. Generic material test reports — such as “aluminium alloy” without reference to a named product — do not satisfy this requirement in most certifiers’ view.
AS/NZS 4284:2008 — Testing of building facades. This standard tests the facade system’s resistance to water penetration, air infiltration, and structural performance under simulated wind pressure. The specification should state the serviceability limit state (SLS) pressure the system must be tested to, which is determined by the project’s wind region and building height.
For most commercial and multi-residential projects in Australian metropolitan areas, a test result at plus or minus 1500Pa SLS is a reasonable baseline. Higher-exposure sites — coastal, elevated, or cyclonic regions — may require higher pressures, and the facade engineer’s wind load analysis should inform the specification.
NCC 2022 Volume 1 — specifically C2D10. This is the Deemed-to-Satisfy provision for external walls and common walls in Type A and B construction. C2D10 sets out the non-combustibility requirements and lists certain materials that are deemed non-combustible without testing — concrete, stone, terracotta, and common construction metals. For aluminium facade products, the specification should reference C2D10 and require evidence of non-combustibility through AS 1530.1 testing.
Beyond these three, the specification may also reference:
- AS 3715:2002 for powder coat finishes
- AAMA 2605:2020 for PVDF paint systems
- AS 1231:2000 for anodised aluminium
- AS/NZS 1170 for structural design actions (wind loads)
What test evidence should the specification require?
This is where specificity matters most. A specification that says “the product shall comply with all relevant Australian Standards” is well-intentioned but practically useless. It does not tell the contractor what reports to obtain, does not tell the supplier what to provide, and does not give the certifier anything to assess against.
Instead, the specification should list the evidence explicitly:
- AS 1530.1 non-combustibility test report from a NATA-accredited laboratory, naming the specific product
- AS/NZS 4284 facade test report demonstrating performance to the SLS pressure stated in the specification
- AS 1530.3 fire properties test report, if required for internal lining applications or by the project fire engineer
- Coating performance certification to the relevant standard (AS 3715, AAMA 2605, or AS 1231)
- Product data sheet confirming material properties, dimensions, and weight
Each report should be identified by report number, testing laboratory, and NATA accreditation number. This level of specificity makes it straightforward for the contractor to compile the documentation pack and for the certifier to verify it.
How should substitution be handled?
This is one of the most consequential decisions in a facade specification. The phrase “or approved equivalent” appears in most specifications, and in most cases it creates more problems than it solves.
An equivalent product needs to be equivalent across every compliance dimension: material composition, fire test results, weather performance, structural capacity, dimensional compatibility, and finish quality. Assessing that equivalence takes time, documentation, and expertise. On a project where the program is tight, the substitution assessment often happens too late, with too little rigour, and under commercial pressure.
The specification should define what “equivalent” means in measurable terms:
- Must be non-combustible to AS 1530.1 (NATA-accredited report required)
- Must be tested to AS/NZS 4284 to the same or higher SLS pressure
- Must achieve the same or better AS 1530.3 indices
- Must match the specified dimensions and fixing compatibility
- Must carry equivalent warranty terms
If the specification simply says “or approved equivalent” without defining these criteria, the substitution decision defaults to whoever has the least information and the most commercial pressure, which is almost never a good outcome for the project.
What are the most common specification mistakes?
Referencing standards without requiring evidence. Stating that cladding “shall comply with AS 1530.1” without requiring the test report means there is no mechanism for anyone to verify compliance before the product is installed. The requirement has no teeth without the evidence obligation.
Using generic material descriptions instead of product names. “Aluminium rainscreen cladding” could describe dozens of products with very different compliance positions. Naming the product creates a clear benchmark, and if substitution is permitted, the named product becomes the standard against which alternatives are measured.
Omitting the SLS pressure for AS/NZS 4284. Specifying weather performance testing without stating the required pressure level leaves the assessment open to interpretation. The facade engineer’s wind load analysis should drive this number, and the specification should state it.
Not requiring NATA accreditation. Test reports from non-accredited laboratories may not be accepted by certifiers. The specification should explicitly require NATA-accredited testing to avoid late-stage documentation disputes.
Separating fire compliance from the materials clause. Some specifications address fire requirements in a general compliance section rather than tying them directly to each facade product. This makes it easy for the fire requirements to be disconnected from the specific products being procured. Keeping the compliance requirements within or directly adjacent to the materials clause ensures they travel together through the procurement process.
How does Valmond & Gibson support the specification process?
Valmond & Gibson supplies facade products with comprehensive compliance documentation already in place. For interloQ, this includes an AS 1530.1 non-combustibility report (CSIRO report FNC12595), an AS/NZS 4284 weather performance report at plus or minus 1500Pa SLS (report 2022-031-S1), and a 67-page technical manual. For element13, the documentation extends to AS 1530.1 (CSIRO report FNC12545), AS 1530.3 fire properties (CSIRO report FNE12552), AS/NZS 4284 (report 2022-031-S2), AAMA 2605 coating certification, and impact resistance testing.
All test reports are from NATA-accredited laboratories with report numbers that can be cited directly in specifications. If you are writing a facade specification and need product data, test report references, or technical support, our team can help.
Writing a facade specification for an upcoming project? Talk to our team for compliance packs, test report references, and specification support.
Related Reading
- Common Facade Specification Mistakes That Delay Projects
- How to Build a Compliant Facade Documentation Pack
- Evidence of Suitability Under NCC 2022: What Certifiers Actually Need
- NCC Facade Requirements by Building Class: A Practical Guide
Last updated: 4 April 2026