New research has backed the accuracy of NSW’s bushfire risk mapping, but experts warn it may need updating in future because of climate change.

The study found 94% of houses and other buildings destroyed in the 2019-20 Black Summer fires were within 100 metres of flammable vegetation.

In NSW, areas within 100 metres of flammable vegetation are considered bushfire-prone.

When researchers overlaid data for 8656 buildings onto the NSW Rural Fire Service’s official bushfire risk zones, they found 81% of losses were inside the designated areas.

While the 100-metre mark holds up for most conditions and confirms the official bushfire map is a reliable tool, properties further away are at risk during extreme fires, according to the research led by Associate Professor Owen Price, director of the University of Wollongong’s Centre for Environmental Risk Management of Bushfire, and Professor David Bowman from University of Tasmania.

“As extreme fire weather becomes more frequent, there are grounds for revisiting that distance in risk mapping, and for focusing intensive fuel management on the edges of flammable bushland,” Professor Price said.

Climate change is increasing the frequency of extreme fire weather, he says.

Buildings that burnt outside the 100-metre mark were still within 200 metres of flammable vegetation and were destroyed by embers.

The research found five times as many houses were lost next to eucalypt forests than to other flammable vegetation such as grassland and rainforest.

Nearly 75% of homes lost in the Black Summer bushfires were close to eucalypt forests.

“What we hadn’t done before was directly test how different types of vegetation compare,” Professor Price said. “Our results show that eucalypt forest stands out.

“That’s a clear signal about where the risk is greatest, and it can help communities and planners decide where to focus their preparation.”