What is a seismic ordinance? 

A seismic ordinance is a law passed by local authorities requiring the evaluation and retrofit of specific building types proven to be vulnerable to seismic events. These ordinances are created in response to poor performance of certain classes of structures during previous earthquakes, such as the 1989 Loma Prieta earthquake and the 1994 Northridge earthquake. These ordinances outline minimum requirements for mandatory evaluation and structural improvements intended to reduce earthquake-induced damage to classes of buildings identified to be particularly vulnerable to earthquake damage. In general, these ordinances are not intended to strengthen buildings to the same level of seismic performance  of a new building designed using current building code requirements. Rather, these requirements address critical safety concerns by increasing the likelihood that occupants are able to safely exit the building in the event of an earthquake.

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Is your building type included? 

The new generation of seismic ordinances is typically categorized by one of four building types: (1) Wood-Frame Soft-Story Structures, (2) Non-Ductile Concrete Structures, (3) Reinforced Concrete or Masonry Wall Structures, and (4) Pre-Northridge Steel Moment Frame Structures. Most of these newer ordinances apply to structures permitted for construction before a designated date; this designated date varies by ordinance type and municipality, but is generally based on the building code in affect at the time the structure was designed. Follow the links on this page for more information on each building type and the associated ordinance(s).

In California, there are also older mandatory seismic ordinances that apply to other structure types such as unreinforced masonry (URM) buildings. The California URM Law was passed in 1986 and required local governments in high seismic zones to develop an inventory for URM buildings and establish a loss-reduction program. For a handful of California cities, ordinances requiring seismic retrofit were passed—but in the majority of cities, the local ordinances only required that owners identify buildings as being vulnerable. Typically, mandatory compliance dates for URM buildings in California covered by this older generation of seismic ordinances have passed, meaning that most of the buildings in California covered by these older ordinances should be in compliance. Because of this, SeismicOrdinances.com does not address URM ordinances in California. Those requiring specific information on URM ordinances in California should contact their municipality directly.