The City of Richmond Planning & Building Services Department is preparing an inventory of potential soft story buildings in the City. A soft story building is a multi-story building with one or more floors which are “soft” due to structural design. These floors can be especially dangerous in earthquakes, because they can not cope with the lateral forces caused by the swaying of the building during an earthquake. As a result, the soft story may fail, causing what is known as a soft-story collapse. Soft story buildings are characterized by having a story which has a lot of open space. Parking garages, for example, are often soft stories, as are large retail spaces or floors with a lot of windows in the walls. While the unobstructed space of the soft story might be aesthetically or commercially desirable, it also means that there are fewer opportunities to install shear walls, specialized walls which are designed to distribute lateral forces so that a building can cope with the swaying characteristic of an earthquake. If a building has a floor which is 70% less stiff than the floor above it, it is considered a soft story building.
The purpose of the inventory being developed is to identify potential soft story buildings and to alert the property owners and tenants of the potential risk of damage and/or loss of life in an earthquake, in addition to assisting owners of soft story buildings in locating funding to retrofit the building. Furthermore, it is the goal of the inventory to promote public safety by identifying those buildings in the city which exhibit structural deficiencies, and by accurately determining the severity and extent of those deficiencies in relation to their potential for causing loss of life or injury.
Staff, the Association of Bay Area Governments (ABAG) and local professionals hosted a homeowners workshop to provide additional information and answer questions about earthquake hazard reduction and soft story buildings on August 31, 2011 in the City Council Chambers. The entire 90 minute workshop can be viewed at http://www.kcrt.com/series/earthquake-softstorybuildings.html Staff will hold addition workshops, presentations and meetings in the future.
Building Inspector - Building Division
Telephone: (510) 620-6764
Fax: (510) 620-6858