San Francisco ADU Building Permit Guide

San Francisco ADU projects require building permits and can involve multiple units, seismic work, variances, certificates of appropriateness, and higher-cost review.

Permit takeaway

San Francisco says a building permit is required to do construction for an accessory dwelling unit.

Zoning and placement

ADU projects can take longer when they include multiple ADUs, seismic work, variances, or a Certificate of Appropriateness.

Building and trade review

Project plans, property conditions, and scope determine which process applies before a building permit can be issued.

Call before applying when

Call before applying if the ADU changes occupancy, adds units, includes seismic work, affects a historic property, needs a variance, or changes utilities.

Documents to prepare

• ADU building permit application
• Project plans
• Property and unit information
• Seismic, variance, or historic documents if applicable

Inspection planning

• Follow the ADU permit process
• Respond to agency review
• Schedule building and trade inspections
• Keep final approval records

Official sources

• San Francisco ADU Building Permit
• San Francisco Building Permits

This guide is a planning summary. Always verify the current requirements with the local office before starting work.