Australia– The Victorian Bushfires Royal Commission has demanded new national guidelines for bushfire bunkers be ready by April – one of a host of recommended changes to building standards in fire-prone areas.
In its second interim report, tabled to the Victorian parliament on Tuesday, the commission says there is a strong case for immediate revision of construction requirements in areas at risk of bushfires.
It has ordered Standards Australia to publish amendments to the building code no later than the end of March.
Citing evidence given by CSIRO scientist Justin Leonard, the commission says it wants the standards changed relating to buildings on unmanaged grassland, and increased ember protection for properties classified as being at low risk of bushfire attack.
At present unmanaged grassland is not considered when assessing a site’s bushfire attack level, except in Tasmania.
Mr Leonard told the commission evidence from recent fires highlighted the significant risks buildings face from grassland fuels.
“There seems to be no reason for this issue not to be dealt with by an immediate amendment to (the building code),” the commission said in its report.
The commission wants standards lifted in relation to sarking – the practice of installing material such as reflective foil behind wall cladding as a secondary ember protection measure.
At present there is no requirement that sarking-type material have any particular fire-resistant qualities.
“If sarking is to be used as a secondary ember protection measure, only sarking that has a sufficient level of fire resistance to be an effective barrier should be prescribed,” the commission said.
The commission has ordered Standards Australia to report to it on the progress of amendments to the building code to boost ember-protection measures for properties at low risk of bushfire attack, especially in regard to sub-floor requirements and materials prescribed for doors, windows and wall barriers.
The Australian Building Codes Board has committed to releasing a standard for bushfire bunkers no later than April 30.
The standard will address factors such as fire and high wind resistance, structural strength, minimum size and maximum occupancy.
The state government has put in place its own bushfire bunker and shelter accreditation system that will operate until the national standard is put in place.
The commission wants the government to amend its building regulations to reflect the national standard no later than May 31.
It has heard evidence from people who successfully sheltered in bunkers.
But seven people died in bunkers or bunker-like structures on Black Saturday.
The commission said the evidence showed extreme caution should be taken in using bushfire bunkers as part of a household’s bushfire plan.
“While a well designed and constructed bunker may provide a temporary place of refuge during the passage of the fire front, bunkers are not a panacea,” the commission said.
“Misplaced reliance on a bunker can be life-threatening.”
The commission’s hearings are continuing, with its final report due by July 31.