Check earthquake safety rules

Your construction project may require earthquake safety improvements if it includes any of these:

• Horizontal addition that adds more than 30% to the size in square feet of the building
• Structural alterations to more than 30% of the floor and roof areas
• Changes to walls and ceilings on more two-thirds of the stories of the building
• Change of occupancy of more than 100 people
• Adding 3rd dwelling unit in a below-ground basement
• Adding an accessory dwelling unit (ADU)

Some wood-frame, multi-family buildings in San Francisco require seismic upgrades under the mandatory Soft Story program.

Search the Soft Stories property list to see if you are affected.

Learn about the Soft Story program

See more in our administrative bulletins:

• Administrative Bulletin 106 for implementation procedures for Seismic Strengthening of Soft Story Wood Frame Buildings
• Administrative Bulletin 107 for Engineering Criteria of Seismic Strengthening of Soft Story Wood Frame Buildings

If you choose to do voluntary soft story work or seismic upgrades, follow these instructions in our administrative bulletins:

• Definition and Design Criteria for Voluntary Seismic Upgrade of Soft-Story, Type V (wood-frame) Buildings (AB-094)
• Application of California Existing Building Code, Appendix Chapter A3 (AB-108)