Last updated: January 2026 · 4 min read
San Jose ADU / Accessory Dwelling Unit Guide
San Jose homeowners interested in adding an Accessory Dwelling Unit (ADU) must obtain approval from the Planning, Building and Code Enforcement Department. Any residential property within San Jose city limits seeking to construct a new or convert an existing structure into a secondary dwelling requires a comprehensive permit process.
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What Requires a ADU / Accessory Dwelling Unit in San Jose
San Jose defines an ADU as a secondary residential dwelling unit located on the same lot as a primary single-family residence. Properties must meet specific zoning requirements, including lot size minimums and setback regulations established by PBCE. Residential zones R-1, R-2, and R-M typically allow ADU construction, though each zone has unique dimensional constraints. Homeowners must demonstrate adequate utility connections, parking availability, and compliance with local building codes before permit approval.
What Doesn't Require a Permit
Minor interior renovations under 200 square feet that do not alter structural elements typically do not require a full ADU permit in San Jose. Temporary structures less than 120 square feet with no permanent utility connections can be installed without formal PBCE review. Existing accessory structures that remain unchanged and do not introduce new living spaces are generally exempt from ADU permitting requirements.
ADU / Accessory Dwelling Unit Costs and Fees in San Jose
San Jose PBCE calculates ADU permit fees using hourly rates and project complexity. The base ADU permit rate is $395.00 per hour, with a two-hour minimum requirement. Additional fees include plan check at $395.00 per hour and permit issuance at $227.00 per hour. A mandatory technology fee of 3% will be applied to the total permit fees. Homeowners should budget for comprehensive review processes that can range from $1,500 to $5,000 depending on project scope.
How Long Does ADU / Accessory Dwelling Unit Approval Take
San Jose's Planning, Building and Code Enforcement department processes ADU permits through a multi-stage review. Typical approval timelines range from 4-8 weeks, depending on project complexity and current departmental workload. Electronic submissions through SJ Permits can potentially expedite the review process. Contractors familiar with San Jose's specific building codes may help streamline documentation and reduce overall processing time.
Required Documents for San Jose ADU / Accessory Dwelling Unit
San Jose PBCE requires comprehensive documentation for ADU permit applications. Mandatory submittal materials include detailed architectural plans, site surveys, utility connection diagrams, and proof of property ownership. Scaled drawings must demonstrate compliance with local zoning regulations, including setbacks, height restrictions, and total floor area calculations. Digital submissions through SJ Permits are preferred and can accelerate the review process.
Step-by-Step Application Process
Navigating San Jose's ADU permit process requires careful preparation and thorough documentation.
- 1
Initial Consultation
Schedule a pre-application meeting with San Jose PBCE to review project feasibility and requirements.
- 2
Document Preparation
Compile comprehensive architectural plans, site surveys, and utility connection diagrams.
- 3
Online Submission
Submit complete application package through SJ Permits online portal.
- 4
Plan Review
PBCE reviews submitted documentation and conducts initial compliance assessment.
- 5
Revisions and Approval
Address any departmental comments and obtain final permit approval.
Required Inspections
San Jose mandates multiple inspection stages for ADU projects. Initial site inspections verify existing conditions and proposed modifications. Subsequent inspections cover foundation, framing, electrical, plumbing, and final occupancy. Each inspection phase costs $442.00 per hour with a one-hour minimum. Homeowners must schedule inspections through PBCE and ensure all work meets current California building codes.
Tips for Faster Approval in San Jose
Successful ADU permit applications in San Jose require meticulous attention to detail. Provide complete, professionally prepared documentation that clearly demonstrates compliance with local zoning regulations. Engage with a licensed contractor experienced in San Jose's specific building requirements. Proactively address potential review comments during initial submission to minimize processing delays.
Frequently asked questions about San Jose adu permits
How much does a ADU / Accessory Dwelling Unit cost in San Jose?
Total permit fees range from $1,500 to $5,000, with base rates of $395.00 per hour for ADU permits and additional fees for plan check and issuance.
How long does it take to get a ADU / Accessory Dwelling Unit in San Jose?
Typical ADU permit approval takes 4-8 weeks, depending on project complexity and current PBCE workload. Electronic submissions can help expedite the process.
Can I apply for a ADU / Accessory Dwelling Unit online in San Jose?
Yes, San Jose offers online permit applications through the SJ Permits portal, allowing digital submission of all required documentation.
Do I need a contractor for a ADU / Accessory Dwelling Unit?
While not always mandatory, a licensed contractor familiar with San Jose building codes can significantly streamline the permit application and construction process.
What happens if I build without a permit in San Jose?
Unpermitted ADU construction can result in significant fines, mandatory removal of the structure, and potential legal complications with the city's Planning, Building and Code Enforcement department.
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San Jose Building Department Contact
Planning, Building and Code Enforcement
200 E. Santa Clara St, 1st Floor, San Jose, CA 95113