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ADU Ally

Accessory Dwelling Units (ADUs)

Accessory dwelling units — also called ADUs, secondary units, or granny flats — are small living units, including a kitchen and bathroom, on properties zoned residential with a single-family home, duplex home, or multifamily building in place. Junior Accessory Dwelling Units (JADUs) are small (less than 500 square feet) that must be converted existing square footage of a single-family home. 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.

There are many benefits to ADUs, 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.
  • A tiny home on wheels (THOW) may be a more affordable approach to an ADU. Please read Bulletin 291-Tiny Home on Wheels Permit Checklist.

If you're exploring how to finance or save money on an ADU, please be sure to check out these additional resources: 

  • Housing Trust Silicon Valley offers free educational workshops as well as financial assistance to Bay Area homeowners who are seeking to build an ADU.
  • One way to lower the overall cost of an ADU is to work with a vendor who offers ADU designs that are preapproved by the City. See our Preapproved ADUs webpage for more information.