September 15, 2013
San Francisco Apartments Soft Story
San Francisco Apartments Soft Story
Source: FEMA
Impact to Structural Engineering History in Northern California

The ordinance applies to wood-frame buildings of three or more stories or two stories over a basement or underfloor area that have any portion extending above grade, and containing five or more residential dwelling units where the permit to construct was applied for prior to January 1, 1978, and where the building has not yet been seismically strengthened.

While these types of buildings and their associated risks are found in every neighborhood in San Francisco, they are most commonly found in the following districts: Mission, Western Addition, Richmond, North Beach, and Marina District.

Following the 1989 Loma Prieta earthquake, this style of construction was found to result in complete collapses more often than any other structure type in the city. As a result, a targeted effort was launched to retrofit these structures before the next major earthquake.


The San Francisco Mandatory Soft Story Retrofit Program (MSSP) was created in 2013 as a multi-year community-based effort led by the Earthquake Safety Implementation Program and enforced by the Department of Building Inspection to ensure the safety and resilience of San Francisco’s housing stock through the evaluation and retrofit of older, wood-framed, multi-family buildings with a soft-story condition.

Related Organization(s)
  • San Francisco Department of Building Inspections
Related Engineer(s)