Sponsored by the Structural Engineering Institute of ASCE Seismic Evaluation and Retrofit of Existing Buildings describes deficiency-based and systematic procedures that use performance-based principles to evaluate and retrofit existing buildings to withstand the effects of earthquakes. This next-generation standard combines the evaluation and retrofit process and puts forth a three-tiered process for seismic evaluation according to a range of building performance levels —from collapse prevention to operational— that marry targeted structural performance with the performance of nonstructural elements. The deficiency-based procedures allow the evaluation and retrofit effort to focus on specific potential deficiencies deemed, on the basis of past earthquake observations, to be of concern for a permissible set of building types and heights. The systematic procedure, applicable to any building, sets forth a methodology to evaluate the entire building in a rigorous manner. Analysis procedures and acceptance criteria are established and requirements put forth for foundations and geologic site hazards; components made of steel, concrete, masonry, wood, and cold-formed steel; architectural mechanical and electrical components and systems; and seismic isolation and energy dissipation systems. In addition, screening checklists are provided for a variety of building types and seismicity levels in support of the Tier 1 process. This standard updates and replaces the previous Standard ASCE/SEI 41-06, Seismic Rehabilitation of Existing Buildings, as well as Standard ASCE/SEI 31-03, Seismic Evaluation of Existing Buildings. Standard ASCE/SEI 41-13 serves structural engineers, design professionals, code officials, and building owners interested in improving the seismic performance of existing buildings.