Seattle URM Project

In October 2023, Seattle City Council adopted Resolution 32111 that supports the development of a voluntary seismic retrofit ordinance that will establish a minimum seismic safety standard for the retrofit of unreinforced masonry (URM) buildings. Seattle has 1,100 URM buildings and an 86% chance of experiencing a damaging earthquake in the next 50 years. Adopting a mandatory URM retrofit ordinance continues to be the City’s long-term goal. However, adding a short-term goal to adopt a voluntary URM retrofit ordinance provides assurance to URM building owners that by retrofitting to the established standard, they will be compliant with future mandatory requirements. SDCI published the 2023 Draft URM Retrofit Technical Standard, an update from the 2012 draft, that will inform the future voluntary retrofit ordinance. The updated standard includes a clearer scope of retrofit and testing requirements to qualify for using the Alternate Method for retrofit. Additionally, the update establishes criteria for recognizing previous seismic retrofits which will help URM building owners understand how future mandatory retrofit requirements may impact them. This presentation will cover development of the retrofit technical standard and the two retrofit methods for URM building owners, the Code-Based Method or the Alternate Method.