Introducing a severe impacts approach to guide adaptation to pluvial floods in residential and public buildings

Damages to buildings from pluvial flooding pose key risks to cities, impacting both economy and health, and drawing increased policy attention. While Swedish buildings are known to be at risk, most research focuses on homeowners and flood exposure. Despite municipal property companies owning a quarter of all apartments in Sweden, less is known about their buildings' risk and adaptation actions. This study addresses this gap by investigating: What do property company staff view as severe pluvial flood impacts? Which building characteristics contribute to pluvial flood risk, particularly severe impacts? What adaptation actions can property companies implement to reduce severe flood impact risk? The study involves collaboration with four Swedish municipal property companies, mapping 2,358 buildings, inspecting 604 buildings, and conducting nine expert workshops. The study suggests a severe impacts approach to guide adaptation to pluvial floods, reducing impacts on: Human lives or health, Critical operations, Evacuation, Critical technical installations, and High-value loss and damage. The study identifies a set of scalable property-level adaptation actions to reduce severe impacts and a typology of adaptation actions, emphasizing property owner responsibility and ability to act. Implementing the severe impacts approach, the typology and scalable actions will increase property companies' capacity to adapt.