Damage to technical elements of the building envelope in the typical multi-risk scenario of the Campi Flegrei area.

Damage to technical elements of the building envelope can have unacceptable consequences for the functionality and safety of a building. Recent interest in such damage is mostly linked to intensive events, neglecting the study of extensive events. Despite the known connection between technical envelope vulnerability and building functionality and safety, systematic vulnerability studies are missing. This study proposes investigation sheets for damaged technical elements as preliminary tools for assessing envelope vulnerability and hazardous events, related to this vulnerability, in urban areas. The study focuses on frequent but non-catastrophic hazards, typical of the Campi Flegrei area, where recent bradyseismic activity has renewed national interest and necessitated risk prevention measures. The research methodology involves three phases: identification of the most vulnerable technical elements, comparison with bibliographic data, and direct application in a multi-risk scenario, specifically bradyseismic activity combined with different environmental exposures. Analysis reveals balconies and cornices as the most frequently damaged elements, particularly vulnerable to bradyseismic activity and environmental exposure. Associations between observed damage and hazard characteristics will support the identification of the degradation pattern of technical elements which is needed to analyse their vulnerability and to assess the risk onto the urban system associate with it.