A study into the Black Saturday bushfires has revealed a need to rethink risk strategies.

The fires ripped through Victoria in February 2009, killing 173 people and causing more than $4 billion damage.

Researchers at the University of Wollongong studied a sample of 3500 houses to explore the effects of nearby forest and “crown” fires, which are caused by flames racing ahead of the main fire through the crowns of the trees.

They found even houses up to 1km from large areas of forest were at risk from crown fire embers. Current zones set by authorities vary from 25-500 metres.

However, the report says clearance of forest up to 1km from houses is “unlikely to be acceptable to the wider community, because of potential environmental consequences and degradation of aesthetic values”.

The researchers say houses are more likely to burn if there are other properties within 50 metres and if they are on a slope.

Study co-author Owen Price says the 1km zone is only relevant to catastrophic weather in forests with very large trees, and would not be required in most regions.

Asked by insuranceNEWS.com.au about the house-to-house spread of fire, he says it is “in the interests of the insurance industry” to ensure all properties meet Australian Standard 3959, which covers building requirements based on bushfire threat.

“At present, only new houses are required to do so, but there is little doubt fewer houses would be lost if they all met the code, and the fires would probably stop at the first row of houses and not spread into the towns,” Dr Price said.

“We are fairly close to a situation where we can map true fire risk to properties based on the historical patterns of ignition spread and house loss. So in theory, insurance premiums could be set to match the risk.”