A wildfire vulnerability index for buildings in Austria

Recent events have clearly shown that wildfires may occur in areas that until now have not experienced large wildfires and the associated consequences (e.g. Scandinavia, Siberia, Austria, etc.). There is a need to understand the risk posed by wildfires and develop tools for the assessment of the vulnerability of assets such as buildings and infrastructure. Building quality and design standards are important not only because building loss is costly but also because robust buildings may offer shelter when evacuation is not possible. Studies aiming at the analysis of wildfire vulnerability for the built environment are limited.  We present a new wildfire vulnerability index for buildings in Austria based on a choice of vulnerability indicators and expert judgement. Vulnerability indicators express characteristics of the buildings and their surroundings that influence their vulnerability to a hazardous process. A list of indicators based on the existing literature has been used together with an expert panel to decide which indicators may be relevant and what is their importance in controlling vulnerability. The indicators and their weights are aggregated into a wildfire vulnerability index which can be assigned for each building located in the wildland urban interface (WUI) zone. This index is related to information such as the structural building type, the roof type, material and shape of the roof, the inclination of the ground, the surrounding vegetation, the material of the shutters and the ground covering. The resulting vulnerability and its spatial pattern may guide decisions, strategies and vulnerability reduction activities that will increase the resilience of communities to this emerging risk. The index may be used by decision-makers, emergency services, homeowners and insurance companies to visualise physical vulnerability to wildfire.