Chapter 3: Establishing Performance Objectives and Project Constraints

An important first step in any assessment and retrofit project is to agree on how project stakeholders would ideally expect the building to behave in an earthquake. Performance objectives in earthquake engineering are defined as one or more combinations of a performance target, a description of how the building is likely to respond under earthquake shaking, and a hazard level, a description of the strength of the ground shaking and how frequently it is expected to occur at the site. This chapter discusses how engineers describe a building's seismic performance and factors that are considered when defining performance targets for assessment and retrofit projects. It then considers typical trade-offs and project constraints that may arise in retrofit projects and how they may impact on these performance aspirations. Finally, performance considerations for different project and client types are discussed, including special issues arising for heritage and earthquake-damaged buildings.