On February 7, 2009, Victoria endured the worst bushfires in the nation’s recorded history.
Black Saturday, as the date is known, claimed 173 human lives and destroyed 2,029 homes. The Victorian Bushfires Royal Commission was established just over a week later to investigate the causes and responses to the disaster.
Now, with bushfire season fast approaching, construction of the first bushfire resistant straw bale house tested by CSIRO has begun in rural Victoria.
The idea has been developed by sustainable designer Joost Bakker, who has based the house on design principles that minimise environmental impact while withstanding temperatures equal to that of a worst-case bushfire scenario.
The design challenges traditional construction methods and materials. The structure is made with straw bale insulation and set into a recycled steel frame with magnesium oxide cladding. Created for Daylesford and Hepburn Mineral Springs company founder Mitch Watson, the new house will be located on a cliff top and feature a grass-covered roof that captures pollution through ‘living’ soils.
Testing was carried out earlier this year by CSIRO fire engineers using a bushfire simulator in Mogo, NSW. The results showed that the design could withstand temperatures in excess of 1,000 degrees Celsius.
“We’ve worked hard together to source materials from local suppliers – on one of my first visits to the Daylesford site I passed a paddock of soon to be harvested oats,” Bakker said. “Mitch asked the local farmer about the potential of baling the straw after the harvest of the crop and the farmer eagerly obliged. Consequently the local farmer’s straw will soon be the foundations and insulation of the new home.”
CSIRO fire safety engineer Alex Webb said the house material reacted very well when tested by CSIRO earlier this year.
“After a period of radiant heat exposure, the fire was intensified to the face of the building at over 1,000 degrees Celsius for almost two minutes, simulating a major fire front,” he said. “The final stage called ‘post fire exposure’ simulated heavy fuel burnout around the house.”
Webb noted that the test results showed the house would be suitable in areas prone to bushfires.
Research completed by CSIRO shows that by 2020, a greater number of extreme fire weather days, longer fire seasons and a greater potential for multiple fire events can be expected.