Where Can I Use Timber Externally? A Guide to NCC Compliance in Australia

Timber is a popular choice for facades in Australia due to its natural aesthetics and sustainability. However, strict fire safety regulations under the Australian National Construction its use is regulated under the Australian National Construction Code (NCC), which sets fire safety standards for different building classes. If you’re considering using timber externally, it’s essential to understand the NCC requirements to ensure compliance.

In this guide, we’ll break down the NCC timber facade regulations, including:

• Where external timber cladding is permitted in different building classes.
• How bushfire attack level (BAL) ratings impact timber facade compliance.
• Why Wood Finish Aluminium facades are a fully compliant, fire-safe alternative.

NCC Volume 1: External Timber Use for Building Classes 2 to 9

For multi-residential, commercial, and industrial buildings, NCC Volume 1 regulates the use of external timber cladding based on the Fire-Resisting Construction Type. This classification depends on building height and class, as outlined in Table C2D2 of the NCC.

Type of construction required

Where Can Timber Be Used Externally?

Class 2, 3, and 9 Buildings (Apartments & Public Buildings)

• Timber cladding is allowed externally if the building is one storey.
• Note, if a garage is underneath, the apartment remains classified as one storey, so timber can still be used.

Class 5, 6, 7, 8 Buildings (Offices, Retail, Storage & Factories)

• Timber cladding is permitted externally up to two storeys.
• For example, a building with a garage beneath and two additional storeys qualifies as two storeys’, permitting timber use. Find out more information here.

Fire Source Feature Proximity Requirements

A fire-source feature is anything that could impact fire safety near a building. This includes the far edge of a road, river, or similar open space next to the property, the property’s side or rear boundary, or the external wall of another non-Class 10 building on the same property. 

Even if timber is permitted in your building class, minimum clearance distances from fire source features apply:

Fire-Protected Timber & NCC Concessions (C2D13)

Under NCC Clause C2D13, fire-protected timber can sometimes be used in place of non-combustible materials. If you’re considering this option, consult a fire engineer and your local building surveyor to determine compliance. 

NCC Volume 2: Timber Use in Class 1 and 10 Buildings

For Class 1 (single dwelling houses) and Class 10 (non-habitable structures), timber can be used externally. However, an important factor to consider is the Bushfire Attack Level (BAL) rating of your site.

BAL Rating Requirements for Timber Facades

If your project is in a bushfire-prone area, your timber facade must comply with Australian Standard AS3959, which governs BAL ratings. Consider the following:

• Choose BAL-rated timber species that meet your site’s fire safety requirements.
• Ensure your external timber cladding meets NCC compliance.
• Consult a building surveyor to confirm suitability before installation.

For high-risk bushfire zones, a non-combustible timber alternative may be required.

According to AS3959 Appendix F, the following timber species can be used in a BAL 29 application.

Bushfire resistance species

The Alternative – Wood Finish Aluminium

A Fire-Safe, NCC-Compliant Facade Solution

While timber is a beautiful and sustainable material, it comes with fire-safety limitations and ongoing maintenance requirements. Wood-Finish Aluminium is an excellent non-combustible timber alternative that delivers the same visual appeal without compliance and maintenance issues.

Benefits of Wood Finish Aluminium

1. Fire Safe & Fully NCC Compliant
   • Non-combustible
   • BAL FZ – This can be achieved in meeting the FRL requirements as prescribed in AS 3959 clause 9.4.1 as a system of 30/30/30 or -/30/30 thereby achieving the highest level of resistance. Also, timber can meet BAL FZ with the addition of Gypsum sheathing boards in the build out. Contact us for more information.
2. Ultra-Realistic Timber Appearance – Achieve the warmth and aesthetics of timber with high-quality finishes.
3. Low Maintenance – No twisting, warping, leaching, or extensive upkeep required.
4. Longer & Straighter Lengths – Provides a seamless, uniform look with fewer joins compared to natural timber.
5. Weather & UV Resistant – Won’t fade, crack, or deteriorate over time.

Download Wood Finish Data Sheet

Questions? Please get in touch.

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