**FREE FOR DOWNLOAD** An electronic copy of this report is available from the FEMA library.
This guidance evaluates current building code triggers, the influence of structural irregularities on seismic building performance (in terms of collapse probability), and the effectiveness of relevant code provisions. The objective of the studies conducted under this project was to inform and improve U.S. codes and standards so that structures with configuration irregularities have a level of safety against collapse in an earthquake that is comparable to that for regular structures. The publication focuses primarily on design requirements for new buildings, with limited consideration of the treatment of irregularities for existing buildings.
Note: FEMA documents are available online free of charge, and in hard copy by contacting FEMA (phone: 1-800-480-2520). The above cost is the cost of handling.