Accessory Dwelling Units (ADUs)

General Information

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 within the existing square footage of a single-family home.

As of January 2020, ADUs and JADUs can be built on most residential properties in California. The information provided here summarizes the benefits for ADUs, provides links to standards, and answers the most frequently asked questions about where, how, and how much can be built as an ADU or JADU. 


There are many benefits to ADUs and JADUs, 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. 

State Legislation and Local Ordinance

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 new Accessory Dwelling Unit Handbook. In October 2020, the City of Watsonville enacted new regulations in accordance to state legislation pertaining to ADUs.

  • The City's adopted ADU Ordinance is codified in Chapter 14-23 of the Zoning Code (Title 14).
  • For a checklist summarizing the information needed for obtaining a Building Permit for an ADU or JADU, click here.
  • Answers to frequently asked questions can be found here.

Contact Information  

For general information and to ask questions about ADUs:   

  • Call: (831) 768-3050
  • Email:

We can help answer questions ranging from constructing a new ADU to legalizing an existing, unpermitted ADU.