The NCC sets different fire performance requirements for external walls depending on building classification and construction type. Not every project needs the same level of compliance evidence, and understanding the distinction early saves time and avoidable hold-ups at certification. This is a practical breakdown of what’s required for each building class and how to demonstrate compliance.
How does the NCC classify building types?
The NCC assigns every building a classification based on its purpose. Classes 1 and 10 are covered by Volume Two (Housing Provisions). Classes 2 through 9 are covered by Volume One, which is where the more demanding fire resistance provisions sit.
For facade work, the classifications that come up most often are:
- Class 2 — Apartments and residential units. The most common classification for aluminium cladding projects, especially mid-rise and high-rise residential.
- Class 3 — Residential buildings other than Class 2, including hotels, motels, boarding houses, and aged care facilities.
- Class 5 — Office buildings.
- Class 6 — Retail premises, shops, and restaurants.
- Class 7a/7b — Car parks and storage/warehouses.
- Class 8 — Factories, workshops, and laboratories.
- Class 9a — Healthcare buildings, including hospitals and day surgeries.
- Class 9b — Assembly buildings, including schools, community halls, and places of worship.
Class 1a (houses) and Class 10 (non-habitable structures like sheds and carports) have their own weatherproofing and structural provisions but generally do not trigger the non-combustibility requirements that apply to multi-storey construction.
Which building types require non-combustible external walls?
This is the central question for facade specification: does your building class and height trigger a non-combustible external wall requirement?
The NCC determines this through construction types. Table C2D2 in Volume One assigns every building a required construction type — Type A, Type B, or Type C — based on its classification and rise in storeys.
Type A is the most stringent. It applies to taller and higher-risk buildings, generally those with a rise of four or more storeys, or three storeys for Class 2, 3, and 9 buildings depending on effective height.
Type B is the mid-tier. It typically applies to buildings of two to three storeys in most classifications.
Type C is the least restrictive, applying to low-rise buildings (generally one to two storeys), and it allows the most flexibility in material selection.
Under the Deemed-to-Satisfy provisions, the rule is straightforward: in a building required to be of Type A or Type B construction, external walls and their components must be non-combustible. This is set out in C2D10, which requires that external walls — including the facade covering, framing, and insulation — be constructed of materials that are deemed non-combustible.
Type C construction does not carry a blanket non-combustibility requirement for external walls, though other fire provisions (such as proximity to boundaries) may still apply.
What are the requirements by building class and construction type?
The following table summarises the general position under the NCC’s Deemed-to-Satisfy pathway. Construction type depends on the specific rise in storeys, so a Class 5 office at one storey (Type C) has very different requirements to the same classification at four storeys (Type A).
| Building Class | Typical Use | Common Construction Type | Non-Combustible External Walls (DtS) | Key Evidence |
|---|---|---|---|---|
| Class 1a | Houses | N/A (Volume Two) | Generally not required | Weatherproofing to Part 7.5 |
| Class 2 | Apartments | Type A (4+ storeys), Type B (2-3 storeys) | Yes (Type A and B) | AS1530.1 test reports, compliance pack |
| Class 3 | Hotels, aged care | Type A (3+ storeys), Type B (2 storeys) | Yes (Type A and B) | AS1530.1 test reports, compliance pack |
| Class 5 | Offices | Type A (4+ storeys), Type B (2-3 storeys), Type C (1 storey) | Yes (Type A and B), No (Type C) | AS1530.1 test reports for Type A/B |
| Class 6 | Retail | Type A (4+ storeys), Type B (2-3 storeys), Type C (1 storey) | Yes (Type A and B), No (Type C) | AS1530.1 test reports for Type A/B |
| Class 7 | Car parks, storage | Type A (4+ storeys), Type B (2-3 storeys), Type C (1-2 storeys) | Yes (Type A and B), No (Type C) | AS1530.1 test reports for Type A/B |
| Class 8 | Factories | Type A (4+ storeys), Type B (2-3 storeys), Type C (1-2 storeys) | Yes (Type A and B), No (Type C) | AS1530.1 test reports for Type A/B |
| Class 9a | Healthcare | Type A (all), except Type B at 1 storey | Yes (Type A and B) | AS1530.1 test reports, compliance pack |
| Class 9b | Schools, assembly | Type A (3+ storeys), Type B (2 storeys) | Yes (Type A and B) | AS1530.1 test reports, compliance pack |
| Class 10 | Sheds, carports | N/A (Volume Two) | Generally not required | Structural and weatherproofing only |
This table reflects general DtS positions. The actual construction type for a specific project depends on the exact rise in storeys and effective height. Always confirm with the project’s BCA consultant or certifier.
What evidence do certifiers need to see?
When non-combustible external walls are required, certifiers need to see that every material in the wall assembly passes AS1530.1 — the combustibility test for materials. This is a pass/fail laboratory test conducted at approximately 750 degrees Celsius. If any single component of the assembly is combustible, the entire system is considered combustible under the Deemed-to-Satisfy pathway.
The evidence needs to be:
- Product-specific. Generic test reports or manufacturer claims are not sufficient. The test must be for the actual product being installed, not a similar product from the same family or a different manufacturer.
- From a NATA-accredited laboratory. In Australia, CSIRO is the most recognised testing authority for AS1530.1, but any NATA-accredited lab is accepted.
- Current and traceable. Reports should be clearly linked to the product through report numbers, material descriptions, and traceability to the manufacturer.
For aluminium facade systems, the compliance documentation typically includes:
- AS1530.1 non-combustibility report for the cladding material itself
- AS1530.1 or deemed non-combustible status for sarking and membranes (noting that C2D10(6)(f) provides a concession for sarking-type materials under 1mm thick with a Flammability Index of 5 or less)
- Non-combustibility confirmation for framing, fixings, and insulation
- Weather performance testing to AS/NZS 4284
At Valmond & Gibson, our compliance packs for interloQ, element13, 165CW, and conneQt include CSIRO AS1530.1 test reports, weather performance testing, and supporting documentation structured for certification submissions. interloQ carries CSIRO report FNC12595 confirming non-combustibility, and element13 carries FNC12545 along with AS1530.3 fire performance testing. Product-specific, NATA-accredited results — not generic data sheets.
What about Performance Solutions?
The Deemed-to-Satisfy pathway is the most common route, but it is not the only one. The NCC provides three compliance pathways: DtS Solutions, Performance Solutions, or a combination of both.
A Performance Solution is a tailored fire safety strategy developed to meet the NCC’s Performance Requirements (CP1 through CP9 for fire safety) without following the prescriptive DtS provisions. This pathway is used where the facade design involves complex geometries, mixed materials, or where a DtS solution would be impractical.
Performance Solutions require a qualified fire engineer who develops and documents the alternative compliance strategy, typically involving fire modelling, risk assessment, and standards such as AS 5113 or BS 8414 (full-scale facade fire testing).
V&G supplies the compliance documentation and test evidence that feeds into either pathway, but we do not provide fire engineering services. If your project requires a Performance Solution, work with the project’s fire engineer — we can provide the technical data they need.
Are there state-specific requirements on top of the NCC?
Yes. Several states have introduced additional requirements that sit on top of the NCC, largely in response to the combustible cladding crisis that accelerated after the 2014 Lacrosse building fire in Melbourne.
New South Wales introduced the Design and Building Practitioners Act 2020 (DBPA), which requires registered design practitioners to issue design compliance declarations for regulated designs, including facades. Panels with a core of more than 30% polyethylene by mass are banned in external cladding. Building practitioners must provide building compliance declarations before an occupation certificate can be issued.
Victoria has the most extensive cladding rectification program in the country, with over $600 million allocated and the program extended to 2027. The VBA applies additional scrutiny to facade materials, and the audit program has driven heightened awareness among certifiers.
Queensland implemented a three-phase combustible cladding approach: identification, fire risk mitigation, and rectification. Private building owners were required to complete the combustible cladding checklist by May 2021, and remediation work continues.
These state requirements do not replace the NCC — they add to it. A project in NSW must comply with both the NCC pathway and the DBPA’s practitioner and declaration requirements. The practical effect is that documentation standards in these states tend to be higher than the NCC baseline, and certifiers expect more thorough compliance packs.
How does this apply to aluminium facade systems?
Solid aluminium and extruded aluminium are listed as deemed non-combustible materials under C2D10(5)(d) of the NCC — “aluminium, including aluminium alloy.” This means solid aluminium products do not need to rely solely on AS1530.1 testing to demonstrate non-combustibility under DtS, though having independent test reports provides additional assurance and is standard practice for certification submissions.
This is a meaningful advantage over composite panel systems (ACPs), where the core material determines combustibility. An ACP with a polyethylene core will fail AS1530.1. A solid aluminium panel or extruded aluminium profile passes.
For Type A and Type B buildings — which covers the majority of Class 2, 3, 5, 6, and 9 projects above two storeys — solid aluminium facade systems sit comfortably within the DtS pathway. The test evidence exists and the materials are clearly addressed by the code.
Getting it right from the start
The NCC framework for external walls is logical once you map it: identify the building class, determine the construction type from rise in storeys, and the compliance pathway follows. For Type A and B construction, external walls must be non-combustible under DtS, and the evidence required is product-specific AS1530.1 testing from a NATA-accredited lab.
The delays we see on projects are rarely about the code itself — they are about documentation arriving late, test reports that do not match the specified product, or compliance packs that are incomplete. Starting with the right material selection and having the evidence ready from specification stage avoids these problems.
If you need compliance documentation for interloQ, element13, 165CW, or conneQt, our technical team can provide the relevant test reports and compliance packs. That is what we do.
Related Reading
- NCC Compliance for Mixed-Use Buildings
- Performance Solutions vs Deemed-to-Satisfy
- Evidence of Suitability Under NCC 2022: What Certifiers Actually Need
- Combustible Cladding Bans by Australian State: 2026 Update
Last updated: 3 April 2026