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Secondary Units or Accessory Dwelling Units (ADUs)
Secondary units — also called accessory dwelling units, ADUs, or granny flats — are small living units, including a kitchen and bathroom, on a property that has a single-family home. There are many benefits to ADUs, including that they:

  • Create more affordable housing for our community, family members, or disabled persons;
  • Provide an income opportunity for homeowners;    
  • Promote infill development; and
  • Encourage the use of public transportation.

Properties that qualify for an ADU
  • Single-family lots that are 3,000 square feet or larger may qualify.
  • View the ADU/Secondary Unit Information handout for rules and answers to common questions.
  • ADUs must comply with the development standards outlined in Section 20.30.150 of the Zoning Ordinance, which are summarized on the handout, in order to obtain a building permit.

Are you ready to proceed with an ADU project? Take these following steps:

Step 1 - Meet with a City Planner--it's free

The first step is to meet with a City Planner and bring:        

  • A completed ADU/Secondary Unit Review Worksheet 
  • A preliminary site plan (may be hand-drawn) that shows:
    - Lot boundaries and dimensions
    - Location of the primary dwelling unit
    - Location of proposed ADU.
  • If you need to remove an ordinance-size tree to build the ADU, also ask the Planner about tree removal.  

During this free consultation, the Planner will check that the project proposal complies with zoning code standards. This is a critical step BEFORE you invest in building plans. The Planner will initial the form and return it to you.
 
This worksheet, initialed by a Planner and signed by the property owner, must be submitted with your building permit application.

         
For the consultation, no appointment is needed. Come to the Permit Center, 1st floor, City Hall. Upon arrival:
 
» 
Go to the Permit Center kiosk to obtain a ticket to meet with a Planner.
» Tap "Planning Services" button
» Tap "ADU Questions" button. Take the issued ticket.
» When your number is called, you'll go to the round Assistance Desk.

Step 2 - Does your project need a clearance from Public Works? 

Is your lot in a geologic hazard, seismic, or flood zone? Find out by visiting www.sjpermits.org. Enter your property address and it will bring up a list of conditions associated with your lot.
  • If your lot is in a geologic hazard or seismic zone, before you apply for a building permit, you will need to read the instructions and complete the Geologic Hazard Clearance application
  • If your lot is in a flood zone, you do not need a clearance but you will have additional requirements for your ADU design and plans.

For questions, call the Permit Center at 408-535-3555 and ask to speak with a Public Works representative.

Step 3 - Prepare plans and apply for a building permit        

A building permit is required to build an ADU or install a modular unit. To obtain a permit:    

    
Fees for ADUs


The scope of your project will determine your permit fees. See the 
Building Division Fee page for building permit fee information. In addition, applicants for an ADU will be required to pay:


  • School Fees
  • Park Impact Fees. View the map that shows the Park Impact Fees that vary according to location.
  • Any fees for other processes as may be needed, such as a Geologic Hazard Clearance or a Tree Removal Permit, 

ADU Parking Requirements and Exemptions

An ADU requires one parking space unless the property qualifies for an exemption under State law. Many ADUs qualify for an exemption. Here are the codes that apply:

Municipal Code 20.90.220(B)(2) - When a garage, carport, or covered parking structure is demolished or converted in conjunction with the construction of a Secondary Dwelling, and the required off-street parking spaces that were provided by such garage, carport, or covered parking structure, are required to be replaced on-site, the replacement spaces may be covered spaces, uncovered spaces, or tandem spaces, or replaced by the use of mechanical automobile parking lifts and in any setback area unless specific findings are made that tandem parking and parking in setback areas is not feasible based on specific site or regional topographical or fire and life safety conditions.

Exemptions - Municipal Code 20.30.150.I - No additional parking shall be required for an ADU that meets any of the below criteria.

  1. The secondary dwelling is located within one-half mile of, and has a path of travel that is always publicly accessible to a site containing an existing public rail-transit station or at least one public bus stop.
  2. The secondary dwelling is located within a historic district identified in the city's historic resources inventory as defined in Chapter 13.48 of Title 13 of this Municipal Code.
       
  3. The secondary dwelling is part of the existing primary residence, or within, or part of, an existing Accessory Building.
       
  4. When on-street parking permits are required but not offered to the occupant of the secondary dwelling.
       
  5. When there is a motor vehicle that is operated as part of a regional fleet by a public agency or publicly-leased motor-vehicle-sharing organization and provides hourly and daily service located within one block of the secondary dwelling.


2018 Secondary Unit Ordinance Changes


Based on public input and public hearings before the Planning Commission, in mid-2018 the City Council approved updates to Section 20.30 of the Zoning Code to ease requirements for ADUs. 
The changes are now expressed in Section 20.30.150 of the Zoning Ordinance. The table below reflects the changes.

Item             Prior Regulation             Regulation
            Effective July 27, 2018
Zoning District ADUs allowed in R-1, R-2, and PD (subject to R-1 standards) zoning districts, which are comprised of single-family residences. Additionally allow ADUs in R-M zoning districts, and in any Planned Development (PD) district where ADUs are not expressly prohibited. Development standards of the Municipal Code and of planned developments zones apply in all cases.
Minimum Lot Size 5,445 sf 3,000 sf
Minimum Setbacks from Rear and Side Property Lines 0 feet – Conversions 5 feet – New construction 0 feet – 1-story conversions 5 feet – New construction or for ADUs constructed above a garage or accessory structure.  
Maximum Height Single story – 18 feet maximum No 2nd-story unit allowed Single story – 18 feet maximum
2nd-story allowed – 22 feet maximum*  *Either an ADU atop a garage or accessory structure or a two-story ADU.
Rear Yard Coverage Not including pools, not more than 40% of the rear yard may be covered. No change
Detached ADU Location Rear yard only, at least 6 feet away from primary dwelling, attached only to a detached garage. Rear yard only, at least 6 feet away from primary dwelling, attached to a detached garage or other existing accessory structure.
ADU Size
(in sf)

Lot Size (sf)

ADU Maximum Size (sf)

3,000 - 5,444

Not allowed

5,445 - 9,000

600

9,001 - 10,000

650

10,001 - Up

800

Lot Size (sf)

ADU Maximum Size (sf)

3,000 - 5,444

600

5,445 - 9,000

700

9,001 - 10,000

800

10,001 - Up

900

Number of Bedrooms Studio or 1 bedroom Under 800 sf: Studio or 1 bedroom allowed 800 sf and up: 2 bedrooms maximum allowed
Attached ADU Maximum Floor Area May not exceed 50% of the existing primary dwelling living area May not exceed 50% of the existing or proposed primary dwelling living area
Design Standards   Match appearance, and match roof form and pitch Require visual compatibility with existing primary dwelling.
Parking requirements Parking configurations in conformance with State law

An ADU requires 1 space unless the property qualifies for an exemption under State law—see the Parking section of this webpage. If a garage has been converted, the main dwelling parking space must be replaced, as uncovered or in front or side setback areas. Parking spaces may be configured on-site per state law.

Reduction in required off-street parking spaces No more than one dwelling occupies the lot. (Section 20.90.220) No more than one dwelling, in conjunction with an ADU, occupies the lot.
Junior ADU Not allowed Removed from consideration; not part of the approved ordinance.
Front yard paving No more than 50% of the front setback may be paved with any impervious surface. (Section 20.30.440) No more than 50% of the front setback may be paved with any impervious or pervious surface.
ADU requirements for lots in Historic Resources Inventory Requires Single-Family House Permit Waive requirement for a Single-Family House Permit for detached ADU or for conversion of existing accessory structure with no exterior alterations.