Decision-making under uncertainty for buildings exposed to environmental hazards

Buildings are exposed to risks from environmental hazards such as earthquakes, windstorms and floods. Substantial uncertainties from various sources are inevitably involved in the risk estimation and decision-making for activities such as design and disaster risk mitigation for buildings. Decision makers seek to achieve economic efficiency while ensure building safety by managing the extreme tail risk that is typically a concern when facing low-probability, high-consequence events. Thus, risk preferences and tolerances play an important role in the decision process, which often vary among different decision makers. The conventionally used minimum expected life-cycle cost criterion (MELC) fails to adequately cope with large uncertainty and risk preferences. To this end, this paper presents the application of a set of decision models beyond the MELC to support decision-making under uncertainty for buildings exposed to environmental hazards. The objective is to provide risk-informed decision support for decision-makers with a wide range of risk appetites while taking into account uncertainties involved in the life-cycle cost. The features, strengths and weaknesses of these decision models are discussed from a practical point of view. The application and selection of the decision models are demonstrated by two practical decision problems: (i) seismic design of a high-rise commercial building, and (ii) wind hazard mitigation for a low-rise residential building. These examples illustrate how the decisions for choosing seismic design levels and wind mitigation measures vary when different decision models and model settings are applied.