Introduction of Performance Criteria into Chapter 1 of ASCE 7-10

Since its inception, the purpose of the ASCE 7 standard has been to set minimum design loads for buildings and other structures, such that they would provide safe and reliable service. It has never been intended to comprise a complete design standard, deferring for the most part to other industry standards for requirements for determination of strength and detailing. Because reliable seismic performance is as much dependent on structural detailing as it is strength and stiffness, the seismic chapters have also included detailing requirements as a condition of loading determination. The 2010 revisions to Chapter 1 of the standard take a major step towards conversion of the document into a comprehensive design standard with the introduction of a performance-based design alternative. The Performance-based design process is one of setting performance criteria then evaluating the ability of a design, either through testing, simulation or a combination of these, to meet these criteria. As such, design loading, in the conventional sense is not used, but rather design scenarios, which include consideration of inherently uncertain loading events and equally uncertain structural response, must be evaluated. Initially, the performance-based option is likely to see most application in seismic and force-protection design, where it already experiences wide use. However, as engineers become more familiar with this approach and the freedom it provides, it will likely see wider use with satisfaction of performance criteria being the primary objective of design.