ADU Jurisdiction Guide: San Jose County
Fees and Regulations (May 2022)
- R-1, R-2, R-M, or PD
- Zones can be found on www.sjpermits.org
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
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
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
- Phone: 408-793-5302
- Email: email@example.com
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.