Accessory dwelling units (ADUs), also called secondary units or granny flats, are small living units with a kitchen and bathroom. They can be on residentially zoned properties, including single-family, duplex, or multifamily properties. The ADU Universal Checklist will help you identify if your property qualifies for an ADU.

Junior Accessory Dwelling Units (JADUs) are less than 500 square feet and located within the footprint of a single-family home. They may be converted from the existing square footage of a single-family home and this can include an attached garage. JADU information and requirements can be found on the JADU Zoning Ordinance.

Tiny homes on wheels (THOWs) are a type of ADU; they are allowed only on single-family properties and have different requirements and a simpler, lower-cost permit process. They are a lower-cost alternative to an ADU. Please read Bulletin 291-Tiny Home on Wheels Permit Checklist. 

There are many benefits to ADUs, JADUs, and THOWs, including that they:

• Create more affordable housing for our community and families;
• Provide an income opportunity for homeowners;
• Promote infill development; and
• Encourage the use of public transportation.

ADU legislation

 If you're interested in the state legislation on ADUs — what’s allowed and where — see the California Department of Housing and Community Development’s Accessory Dwelling Units and Junior Accessory Dwelling Units webpage. The City of San José enacts all state legislation pertaining to ADUs in its zoning code and our ADU Universal Checklist reflects state law.

How many ADUs have been permitted in San Jose? See our ADU Permit Activity Dashboards. We've been tracking permit issuance and construction of ADUs since 2015

Presentation from our July 18, 2023 Building Open House:
Helpful Tips for an ADU Project Presentation: English, Español, Tiếng Việt

We also offer these two videos:

Amazing Tiny Homes on Wheels
Video - Presentation 

Step 1 to Any ADU Project: Property Considerations
Video