ADU Jurisdiction Guide: San Jose City
Fees and Regulations (May 2022)

ADU-allowed Zones

ADU Size Limitations

  • Floor Area: Maximum of 1,200 Square Feet for Lots greater than 9,000 Square Feet
  • Floor Area: Maximum of 1,000 Square Feet for Lots less than/equal to 9,000 Square Feet

ADU Building Height

Single Family ADUs

  • Attached ADU: Same height limitations as apply to the main dwelling unit.
  • Detached ADU: One story: 18 feet maximum. Two-story: 24 feet maximum

Duplex or Multifamily ADUs

  • Attached ADU: Limited to the conversion of existing non-livable space & must maintain existing height.
  • Detached ADU: 16 feet maximum per state law

Minimum Lot Size


Setbacks Requirements

Single Family Homes

  • Attached ADU: Same setback requirements as apply to the main dwelling unit
  • Detached ADU:
    • Must be set back 45 feet minimum from the front property line.
    • Rear/side setbacks less than 3 feet may be subject to fire mitigation measures
    • A second story OR new ADU with greater than 40% rear yard coverage must be set back 4 feet from both rear and side property lines.

Owner Occupancy Requirements


ADU Permit Process

General Process can be seen here.

Average Time for ADU Plan Sets Approval

Overall Process: 6-8 Weeks

ADU Permit Fees (under 750 square feet)

  • Permit Issuance Fee: $386
  • Plan Review Fee: $952
  • Inspection Fee: $1,534

Impact Fees

A permit cost estimate worksheet (attached below) can be submitted to find more accurate permitting fees. School fees and parkland impact fees do not apply to ADUs under 750 sqft.

Water/Sewer Line Connection Fee

If ADU is detached from the residence, it may require a fee to be estimated.

Estimated Mavericks Permit Fees

  • Maverick 392: $2,744
  • Maverick 504: $3,528
  • Maverick 748:  $5,236


Contact References

ADU Ally

  • Phone: 408-793-5302
  • Email:

We hope this quick reference guide helps you out in your ADU project. Part of our service if you build with us is the full service of our in-house permit technician who handle the processing of your permit on your behalf with no mark-ups. 

If you’re interested in building with ADU.Works, please don’t hesitate to book a consultation with us or give us a quick call through our number +1 (650) 227 4810. We’ll gladly discuss the specifications of your permit processing and accommodate any questions you may have. Our team looks forward to hearing from you.

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