Downtime includes the time necessary to plan, finance, and complete repairs on facilities damaged in earthquakes or other disasters. It is an essential component of loss modeling, because it is one measure of operational failure in lifelines and business interruption in buildings. Data from building repairs after the Loma Prieta and Northridge earthquakes, together with institutional risk management projections are used to define the rational and irrational components of downtime for buildings. Rational components include construction costs and time. Irrational situation-specific components take into account the time needed to mobilize for repairs and include financing, relocation of functions, workforce availability, regulatory changes, and economic uncertainty. To quantify these factors, the pace of recovery can be linked to the scale of damage in a stock of buildings in the affected region.

The 12 January 2010 Mw 7.0 earthquake in the Republic of Haiti caused an estimated 300,000 deaths, displaced more than a million people, and damaged nearly half of all structures in the epicentral area. We provide an overview of the historical, seismological, geotechnical, structural, lifeline-related, and socioeconomic factors that contributed to the catastrophe. We also describe some of the many challenges that must be overcome to enable Haiti to recover from this event. Detailed analyses of these issues are presented in other papers in this volume.

Since 1989, earthquakes and hurricanes in the United States have caused housing losses on the same scale as those typically experienced in disasters in under-developed countries. While casualties in the American disasters have been low, the costs of reconstruction have been staggering. This paper documents the housing losses and recovery problems in the Northridge earthquake and compares that experience to other American urban disasters (the Loma Prieta earthquake, Hurricanes Hugo and Andrew), as well as with those in Mexico City and Kobe, Japan. The paper will demonstrate that the common denominator in urban disasters is housing and that recovery issues are quite different in cities than in rural areas, precisely because the losses are concentrated in densely populated areas and the housing loss not only represents a significant financial investment, but also a unique component of the urban infrastructure.

An important task in the effort to improve the resilience of communities to both natural and manmade disasters involves rethinking the current approach for designing individual components within the built environment. In the United States, a patchwork of building codes and engineering standards results in a set of performance objectives for individual components that is often inadequate with respect to the broad principles of resilience. This paper outlines a conceptual framework that can be used to explicitly link community-level resilience goals to specific design targets for individual systems and components within the built environment. It then presents a proof-of-concept example that demonstrates how to derive a consistent performance target for individual residential buildings from a community-level resilience goal. Lastly, it discusses potential applications of the proposed framework, including a critical evaluation of current building codes to verify whether their target performance objectives are compatible with community-level resilience goals.

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