When it comes to using natural materials in construction, fire safety is often one of the first concerns raised—especially in Australia’s bushfire-prone landscape.

But member builder Viva Living Homes is demonstrating that with the right design and rigorous testing, natural materials can not only meet but exceed the fire safety requirements set out in the Building Code of Australia (BCA).

One of their most compelling examples is the performance of their straw structural wall panels, which have undergone full-scale fire testing to determine their Fire Resistance Level (FRL). In one of the key tests, the panels were subjected to temperatures exceeding 1054°C on the fire side, while the non-fire side remained between 34°C and 75°C—well within safe limits for occupied spaces.

More impressively, the walls supported a load of 3.5 tonnes during the two-hour test, achieving an FRL of 120/120/120. This means the panels maintained:

Structural adequacy (supporting the load),

Integrity (resisting flame penetration),

Insulation (preventing heat transfer).

These results confirm that Viva Living Homes’ straw panels meet the highest level of fire resistance required by the BCA—and are also suitable for use in Flame Zone (FZ) areas under AS 3959, Australia’s standard for building in bushfire-prone areas.

A Broader History of Fire Testing in Australia

Viva Living Homes’ testing builds on a growing body of evidence supporting the fire resilience of natural materials:

Strawbale walls have been tested at the CSIRO as far back as the 2000s, showing excellent fire resistance due to their density and plaster coatings.

Earth and mud brick structures have also shown high resistance to fire spread and radiant heat, largely due to their thermal mass and non-combustibility.

Hempcrete has undergone testing to demonstrate non-combustibility and low flame spread, making it another promising material for bushfire-resistant design.

CSIRO Fire Testing of Hempcrete

The CSIRO operates the Fire Technology Centre (FTC) in North Ryde, Sydney, which is equipped to conduct full-scale fire tests on building materials and components . While specific details of hempcrete tests are not publicly disclosed, the FTC’s capabilities include testing materials like hempcrete to simulate various fire scenarios.

Hempcrete’s Fire Resistance

Hempcrete, a mixture of hemp hurd and lime binder, is considered non-combustible and exhibits low flammability. Its fire resistance is attributed to its composition and the chemical properties of the lime binder, which can inhibit combustion. Additionally, hempcrete’s thermal mass helps in delaying heat transfer, providing time for occupants to evacuate in case of fire.

Real-World Fire Performance

In practical applications, hempcrete has shown resilience in fire situations. For instance, hemp blocks at Hemp Squared Pty. Ltd. in Western Australia survived the February Bridgetown bushfire that burned the factory down, indicating the material’s effectiveness in bushfire-prone areas .

Despite their organic origins, many of these materials perform exceptionally well in fire scenarios—often better than conventional lightweight materials, which may ignite or deform under heat.

Why This Matters

There is currently no centralised resource in Australia that catalogues tested natural building systems for compliance with fire standards like FRL or AS 3959. As more builders like Viva Living Homes lead the way with certified systems, they’re not only expanding the possibilities for natural construction—they’re also making it easier for other builders, designers, and homeowners to follow suit.

Conclusion

Through the work of those pushing testing through CSIRo and Viva Living Homes’ it shows that natural doesn’t mean non-compliant. Through rigorous testing and commitment to quality, they’re proving that natural wall systems can meet Australia’s toughest fire standards—even in Flame Zone conditions.

For those interested in building more sustainably without compromising on fire safety, you can get Performance Solutions in high fire zones to build with natural materials. Chat with some of the experts on our Directory today.