A Comprehensive Guide to ADU Regulation and Zoning Policy in San José, CA

Hey San José 👋

Accessory dwelling units have become a growing trend and rewarding prospect for so many homeowners in San Jose over the last few years. This is due in large part to the fact that owning or renting a home in San Jose has become increasingly costly for people that work in the area. As a result, many homeowners have looked to ADUs as a huge opportunity to provide beautiful, spacious, and modern accommodations for short-term guests, friends, family, or long-term rentals.

In our experience, San Jose, CA has one of the best supported ADU programs in the Bay Area. Although each city has its own planning and building department that address questions related to construction and building regulation, San Jose excels with fast-response email service and a comprehensive, yet digestible online resource. If you’re building in San Jose and can’t find the information you’re looking for in our permitting guide, you can visit San Jose’s ADU support page here: https://www.sanjoseca.gov/business/development-services-permit-center/accessory-dwelling-units-adus or contact their ADU Ally via email or phone at adu.ally@sanjoseca.gov or (408) 793-5302. We have reached out numerous times across projects and always receive responses within 24hr if not sooner.

General Notes on San José ADU Regulation

• City of San Jose updated it’s local zoning codes to reflect compliance with the State ADU Mandate on January 2020

• Recent 2019 updates to the California Building Code and California Residential Code are in effect

• Bay Modular’s pre-approved Solo ADU Series is designed to meet the State ADU Mandate and is 100% compliant with the 2019 CBC/CRC

• All Solo ADUs are pre-approved by the State of California Department of Housing and Community Development (HCD #1560585) and do not require any additional local plan check, inspection, or approval

• All site preparation, foundation work, and utility upgrade & connection related to the installation of all Solo ADUs will still require local plan check, and inspection

• Due to statewide updates to ADU regulations, it has never been easier or more affordable to build a permitted ADU

City of San José: Building Department Contact Information

Phone Number: (408) 793-5302
Email Address: adu.ally@sanjoseca.gov
General Resource: https://www.sanjoseca.gov/your-government/departments/planning-building-code-enforcement/building-division
Secondary Dwelling Resource: https://www.sanjoseca.gov/business/development-services-permit-center/accessory-dwelling-units-adus
ADU Application: Download PDF

Location:
City of San Jose: Building Division
200 E. Santa Clara St.
Tower, 2nd Floor
San José, CA 95113

Detailed San Jose ADU Regulations & Guidelines

ADU Size Restrictions (Updated January 2020)

• For single family lots under 9,000 SF

  • Attached ADU may be up to 800 SF or 50% of the primary residence without exceeding 1,000 SF

  • Detached ADU may be up to 1,000 SF

• For single family lots greater than 9,000 SF

  • Attached ADU may be up to 800 SF or 50% of the primary residence without exceeding 1,200 SF

  • Detached ADU may be up to 1,200 SF

• A junior ADU may be up to 500 SF, but must be converted from existing space

• For multi-family lots of any size, either detached or attached may be up to 800 SF, and no junior ADUs are permitted

• A maximum 40% coverage of the rear yard is required

• The minimum size of any living unit is 150 SF

Lot Size Restrictions (Updated January 2020)

• Both single family and multi-family lots will not be subject to the minimum lot size of the underlying zoning district or by ordinance for ADU projects, per AB68

Type of ADUs Allowed

• Detached ADU, attached ADU, junior ADU are all approved (Solo ADU Series are detached ADUs)

• ADUs may be new construction or conversion of existing space (e.g. garage)

• Junior ADUs must be conversion of existing space (e.g. garage)

• California Building Code (CBC) & California Residential Code (CRC) 2019 is in effect

Number of ADUs Allowed (Updated January 2020)

• Single family properties are allowed one ADU and one junior ADU

• Multi-family properties are allowed two detached ADUs. For a duplex, one attached ADU may also be allowed. For multifamily lots, a number of attached ADUs equivalent to up to 25% of existing units may also be allowed

Zoning Requirements (Updated January 2020)

ADUs are allowed in the following General Plan designations:

• Residential Neighborhood or Mixed-Use Neighborhood or Mixed-Use Commercial

• Urban Residential or Transit Residential or Rural Residential

• Downtown or Urban Village

Setback Requirements (Updated January 2020)

• The maximum required setback for a detached new construction ADU shall be no more than 4 feet from the rear and side property lines, 6 feet from the primary dwelling

• Detached ADU must maintain a minimum setback of 45 feet from the front property line

• Setbacks will not be required for ADUs and junior ADUs that have been converted from existing space that was legally established

• Proposed expansions of attached ADUs and conversions from existing space are required to comply with the setbacks of the underlying zone, per AB68

• For corner lots, a 10-foot setback is required on the street side.

Parking Requirements (Updated January 2020)

Parking not needed if ADU is:

• Located within .5 mile of a public bus stop or rail station (see www.vta.org)

• Located in an area where on-street parking permits are required but not offered to the ADU occupant

• Located in within one block of a dedicated car share parking space.

• Located within a historic district listed in the City’s Historic Resources Inventory

Fire Safety Requirements

ADU is only required to provide fire sprinklers if sprinklers are required for the Primary Unit. The fire flow and water pressure on the adjoining streets must meet minimum Fire Marshal requirements.

Architectural Requirements

Detached units do not need to meet any specific design standards. Attached ADUs and detached ADUs on properties listed on the Historic Resources Inventory must incorporate architectural style and elements of the primary dwelling.

Height Requirements

• Single-family properties: 18 feet for a single story, 24 feet for a two-story. If property includes junior ADU, height of detached ADU is 16 feet.

• Multi-family properties: 16 feet.

Ownership (Updated January 2020)

Through 2025, owner occupancy requirements will not apply to new ADUs, per SB13. Owner may rent out both the ADU and primary residence.

Rental Restrictions

ADU may not be rented for a period of less than 30 days.

Utility Connections

A new or separate utility connection may be required, but the connection fee or capacity charge shall be proportionate to the burden of ADU on the water or sewer system.