Recently, San Francisco passed a mandatory Soft-Story RetrofitOrdinance that will require a seismic retrofit of existingbuildings identified as having a soft-story hazard, typically onthe first floor. Though not the first city to enact such anordinance, it is the largest to do so. The ordinance couldaffect an estimated 3,000 number of buildings in San Francisco,primarily multi-family with mixed-use tenants or parking on thefirst floor level.

What is Considered a Soft Story?
Certain buildings have deficient seismic capacity at the firstfloor level (termed a soft or weak story) – i.e., they do notperform well during an earthquake due to a lack of seismicstrength. Examples of soft stories include tuck underparking, glass front walls, and first floors with a much greaterheight than on other floors.

Not all soft stories are seismically deficient; newer buildingsbuilt to more modern building codes will perform better during aseismic event. The SanFrancisco Soft-Story Retrofit Ordinance only applies tobuilding built prior to 1978 that have more than 5 residentialapartment units, and must be at least three stories tall.