Performance-Based Design in risk assessment and reduction

It is now generally accepted that several types of risks can be recognized for built facilities and environments: they are not limited to collapse and heavy damage but involve comfort, quality of life, and the preservation of cultural or historical values. The most rational way of tackling such risks and their reduction is Performance-Based Design PBD (or, better, Performance-Based Engineering) that requires the satisfaction of relevant performance requirements with a sufficiently high probability throughout the lifetime of the facility. This paper presents and discusses the general approach to PBD, and illustrates two examples of application, respectively to aeolian and seismic risk assessment.