A CSIRO report on the Christmas Day bushfires in Victoria identifies “extensive surface litter” and domestic fuels as the main contributors to loss or damage of homes.

The review, commissioned by the Country Fire Authority, finds surface litter provided a “near continuous flammable fuel bed” in Wye River and Separation Creek.

Ignition of heavy fuels such as plastic water tanks, building materials, small garden sheds, boats and kayaks stored under or near houses was also a major contributor, as was the positioning and storage of LPG cylinders.

The report finds “strong evidence” of fire spreading from house to house, despite the generally large distances between buildings – up to 12 metres.

The absence of a “distinct border” between forest and urban areas was another factor contributing to damage or destruction of more than 100 houses.

The CSIRO review highlights weaknesses in building design as contributors to losses.

Emergency Management Commissioner Craig Lapsley says the report reinforces the importance of constructing houses to Australian standards, but that alone will not ensure their resilience.

“What we can take from this report is the need to look holistically at a property,” he said.

“Building to [fire-risk ratings] is very important, but these standards must extend to the surrounds of a property. Ongoing maintenance, vegetation management and safe storage of outdoor furniture, building materials and water tanks are extremely practical, logical and achievable ways we can reduce risk.”

The CSIRO report will be shared with communities, agencies and planning authorities.

“We need to not only learn from this, but to take those learnings and turn them into actions,” Mr Lapsley said.

CSIRO experts conducted surveys of houses in the fire area from January 6-8.

The report is available here.