San Francisco ADU / Accessory Dwelling Unit Guide

San Francisco homeowners seeking to add an Accessory Dwelling Unit (ADU) must navigate strict city regulations. The Department of Building Inspection (DBI) requires detailed documentation and adherence to zoning guidelines for all residential property modifications involving secondary units.

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What Requires a ADU / Accessory Dwelling Unit in San Francisco

San Francisco mandates ADU permits for any residential structure creating a new living space within an existing property or as a separate unit. Typical triggers include converting garage space, constructing backyard units, or transforming basement areas into independent living quarters. The DBI enforces stringent requirements focused on structural integrity, safety standards, and zoning compliance. Property owners must demonstrate the proposed ADU meets minimum square footage, parking, and building code specifications unique to San Francisco's dense urban environment.

What Doesn't Require a Permit

Minor interior modifications under $2,000 might bypass formal permitting. Temporary structures less than 120 square feet and not intended for permanent occupancy often fall outside standard ADU regulations. San Francisco allows limited improvements like painting, minor electrical repairs, and non-structural cosmetic updates without comprehensive DBI review.

ADU / Accessory Dwelling Unit Costs and Fees in San Francisco

San Francisco's ADU permit fees are complex and stratified based on project valuation. The base building permit ranges from $504 for projects under $9,999 to $26,329 for projects between $1,000,000 and $4,999,999. Additional costs include a $10,855 Community Plan Evaluation fee and potential environmental review charges. Consultation services are priced at $283 per hour, with a mandatory one-hour minimum. Contractors should budget for multiple fee categories including permit issuance, site circulation review, and potential demolition expenses.

How Long Does ADU / Accessory Dwelling Unit Approval Take

San Francisco's DBI processing times vary based on project complexity and current departmental workload. Standard ADU permit reviews typically range from 6-12 weeks for comprehensive applications. Simpler projects with complete documentation might achieve faster approval, while complex structural modifications could extend beyond three months. Expedited review options exist for projects meeting specific pre-qualification criteria.

Required Documents for San Francisco ADU / Accessory Dwelling Unit

San Francisco requires detailed documentation for ADU permits, including comprehensive architectural plans drawn to scale, structural engineering calculations, site surveys, and zoning compliance statements. Digital submissions through the SFDBI Portal must include high-resolution floor plans, elevation drawings, and precise measurements. Homeowners must demonstrate compliance with local building codes, setback requirements, and neighborhood architectural standards.

Step-by-Step Application Process

Navigating San Francisco's ADU permit process requires careful planning and thorough documentation.

1. 1

   Initial Consultation

   Schedule a consultation with DBI to review project feasibility and initial requirements.

2. 2

   Document Preparation

   Compile comprehensive architectural plans, site surveys, and engineering documents.

3. 3

   Online Submission

   Submit complete application package through SFDBI Portal with required fees.

4. 4

   Review and Evaluation

   DBI reviews submitted documents for zoning, structural, and safety compliance.

5. 5

   Permit Issuance

   Receive approved permit after successful review and payment of all associated fees.

Required Inspections

San Francisco mandates multiple inspection stages for ADU projects. Initial site inspections verify existing conditions and proposed modifications. Subsequent reviews cover foundation, framing, electrical, plumbing, and final occupancy readiness. DBI inspectors conduct rigorous assessments to ensure full compliance with local building codes and safety regulations.

Tips for Faster Approval in San Francisco

Successful ADU permit applications in San Francisco require meticulous preparation. Engage licensed professionals familiar with local DBI requirements. Anticipate potential challenges by conducting preliminary zoning research and ensuring complete, accurate documentation. Proactively address potential code compliance issues before submission to minimize review delays.

Frequently asked questions about San Francisco adu permits

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