The State Legislature updated Accessory Dwelling Unit (ADU) and Junior Accessory Dwelling Unit (JADU) law in recent years to promote the development of ADUs and JADUs.  With the update of the City's Zoning Ordinance on February 8, 2024, the ADU/JADU regulations consistent with State law are now codified in Chapter 18.60.020. A summary of the regulations that includes diagrams is included in a handout below.  

Starting April 1, 2024, to streamline the permitting process, ADU/JADU projects can be submitted as a Building Permit, except for new attached second-story ADUs on a single-story residence. 

What are ADUs and JADUs? 

ADUs - also called secondary dwelling units, granny flats, in-law units, converted garages, or basement apartments - are flexible spaces that meet the changing needs of households over time. ADUs can be attached or detached from the primary home, are generally between 220 and 1,200 square feet, and must have their own entryway, kitchen, and bathroom.

JADUs are located within the walls of a proposed or existing single-family home, including an attached garage, and are no more than 500 square feet. They also need their own entryway and a small kitchen and may share a bathroom with the main home. 

Getting Started

These resources will help you learn more about ADUs, what is possible on your property, and how to get started:

• Adopted ADU Ordinance, effective 2/8/2024
• SCC ADU Website: Look at floorplans, hear from neighbors about what they built, and download the free ADU Guidebook.
• ADU Process & Important Information: See an overview of the ADU process and things to consider.
• City of Santa Clara ADU and JADU Summary Handout: Learn about ADU and JADU rules and regulations.
• ADU Glossary: Explore frequently used terms.
• ADU Calculator: Estimate potential building costs, rent, and return on investment.

Accessory Dwelling Unit (ADU) Resources

Santa Clara County ADU is a new program offering free resources to help residents through the entire process of building an ADU in Santa Clara County. By encouraging the development of ADUs, our communities can build new homes for our neighbors, children, and grandparents, and help our region thrive. Santa Clara County ADU is one of many efforts of the Santa Clara County Planning Collaborative – a shared initiative among all the jurisdictions in Santa Clara County to help ensure that everyone in the County has access to a safe, secure, and affordable home.