Updated: Aug 2, 2021
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.