Bushfire building safety rules inadequate, inquiry hears
27 August 2009
published by www.theaustralian.news.com.au
Australia — New regulations limiting bushfire risk assessments on building sites to a radius of 100 metres from a planned house were inadequate and potentially misleading, the Black Saturday royal commission was told today.
Under the new regulations a site would be deemed to be at low risk, despite a new house being just 110 metres from a dense forest, building survey Stuart McLennan said.
The new standards, introduced in March following Black Saturday, did not take into account the risk of intense ember attack from vegetation further away than 100 metres, he said.
This was already causing a lot of trouble in areas devastated on February 7, such as Marysville and Kinglake, where the sites of destroyed houses were deemed to be at low bushfire risk under the new rules, yet it was clear they had suffered significant ember attack on Black Saturday.
The 100 metre radius just seems inadequate, Mr McLennan told the inquiry, which is investigating the wildfires that killed 173 people and destroyed than 2000 homes.
A better system would be mapping areas of wider bushfire risk and assessing the dangers of all houses within them from ember attack, based surrounding vegetation such as forests.
All houses in those areas would then have to be built to a standard that resisted ember attack, despite the type of vegetation within the 100 metres radius.
Mr McLennan said the new bushfire attack level test required for all new houses in Victoria was causing concern because people did not know how to properly apply it.
There were no courses or training available on how it uses it.
Under the test, the site of a new house has to be assessed based on its topography and surrounding vegetation to a radius of 100 metres. There are five levels for sites, ranging from low risk to the highest level, known as being in the fire zone.
The assessment of the risk determines the type of house that can be constructed and what fire resistant features must be included.
Mr McLennan, who is a member of the Australian Institute of Building Surveyors, said there was a range of quality in the assessments currently being done by owners and builders because of the lack of training.
He also criticised the new building standards for houses in bushfire areas, saying they were inconsistent and did not take into account whether such preventative features as fire shutters for windows would be regularly maintained to keep them effective.
The Housing Industry Associations national manager for codes and standards, Michael Harding, told the hearing that earlier building standards for constructing houses in bushfire prone areas had been widely ignored or modified by builders because they required the use of products such as fire retardant timbers that were not available.
He said fire retardant timbers had been first required in standards introduced in 1991 and were also required in the updated 1999 standard.
It wasnt well received simply because it wasnt workable, Mr Harding said.
Fire retardant timbers were still not on the market and although fire retardant coatings were available, there were questions about their effectiveness.
It is debatable within the industry whether they work and how long they are effective for, Mr Harding said.