Comprehensive wildfire vulnerability indicators for residential and non-residential buildings in the WUI

Residential and non-residential buildings may react differently to a wildfire due to several factors, including differences in architectural design, construction materials, and the location of combustible or hazardous materials. These differences can significantly influence the level of vulnerability to wildfire impacts, with each type of building presenting unique challenges and risks. While residential structures often prioritise factors such as comfort and aesthetic design, non-residential buildings, such as commercial or industrial facilities, may have additional concerns, such as the storage of large quantities of hazardous materials or the need for specific industrial processes, which introduce further wildfire vulnerabilities.

In this study, we present a comprehensive and detailed set of wildfire vulnerability indicators specifically tailored to assess the risks posed to both residential and non-residential buildings located within the Wildland-Urban Interface (WUI). These indicators are designed to evaluate various characteristics of the buildings themselves, including their construction materials, roof types, and storage of flammable or hazardous materials. In addition to the physical characteristics of the structures, the study also considers the immediate surroundings, such as fences, perimeter walls and the type of vegetation present in the area. Ground cover, which can include grass, shrubs or other combustible materials, is also considered a key factor influencing the vulnerability of buildings to wildfire.

By combining these various building and environmental characteristics, the set of vulnerability indicators provides a holistic approach to assessing the physical risks faced by properties in the WUI. This methodology makes it possible to identify specific hotspots where the risk of wildfire damage may be higher, thus allowing for the prioritisation of prevention measures. For example, buildings with highly flammable roofing materials or those located near dense vegetation may be more susceptible to ignition and therefore require more immediate attention in terms of mitigation strategies.

The practical application of these indicators is demonstrated by their use in assessing the vulnerability of an industrial area located in the WUI in the European Alps. This case study illustrates how the indicators can be used to assess real-world scenarios and highlights areas where improvements can be made to enhance the resilience of both residential and non-residential buildings to wildfire. The study also highlights the importance of a localised, context-specific approach to wildfire risk assessment, as factors such as local climate, terrain and vegetation play a significant role in shaping vulnerability in the WUI. By incorporating these elements, the proposed set of indicators aims to contribute to more effective risk assessment and targeted prevention efforts, ultimately enhancing wildfire resilience in areas where human development intersects with wildlands.