Thank you for joining the Planning Commission for the Accessory Dwelling Unit Study Session on October 7, 2019.

Community Development Staff is currently working on addressing the comments received and will return to the Planning Commission with a draft ordinance within the next few months.  Stay tuned!

 Front of ADU

Photo by: Second Unit Center

What is an Accessory Dwelling Unit (ADU)?

ADUs (Accessory Dwelling Units), also known as granny flats or in-law units, provide independent living quarters for one household with full facilities for sleeping, eating, cooking, and sanitation on the same lot as the primary single-family dwelling. The ADU may be attached, detached, or located within the living areas of the primary dwelling unit on the lot.

Examples of ADUs include:

  • Detached: The ADU structure is detached from the primary dwelling unit
  • Attached: The ADU structure is attached to the primary dwelling unit
  • Converted: The ADU within the existing primary dwelling unit or the ADU was established through conversion of an accessory structure (i.e. garage or pool house)


  • ADUs can provide a source of income for homeowners
  • ADUs give homeowners the flexibility to create a home to share with family members and others, allowing seniors to age in place as they require more care
  • ADUs are a different form of housing that can help San Carlos meet its diverse housing needs
  • ADUs are a critical form of infill-development that can be affordable and offer additional housing opportunities within existing neighborhoods
  • ADUs are an affordable type of home to construct because they do not require paying for land, major new infrastructure, structured parking, or elevators. 

Reason for the ADU Update:

In response to the Bay Area’s regional housing shortages, Governor Brown signed new laws (SB 1069 and AB 2299) from 2016 to 2018 to encourage the construction of more ADUs by reducing the regulatory barriers commonly found in local zoning ordinances. To comply with the updated state policies, the City of San Carlos is undergoing a process of updating its local ADU Ordinance (currently titled Second Dwelling Unit in the City’s municipal code).

Study Session Details:

The City would like to thank the residents and community stakeholders of San Carlos who participated in the ADU Planning Commission Study Session on Monday, October 7, 2019 at 7 p.m. in the City Hall Council Chambers, 600 Elm St., San Carlos.

Some of the topics discussed at the ADU Planning Commission Study Session included maximum floor area for attached and detached ADUs, height requirements and parking. The study session functioned as an open dialogue between the staff, Planning Commissioners, and residents where best practices and policy recommendations were discussed. Staff is processing the feedback and will come back at a later date with recommendations so no formal decision was made during the study session on October 7. Once the Planning Commission develops ADU recommendations, City Council will be the final review authority for the ADU Ordinance.

There will be additional Planning Commission meetings in November so please continue checking the City website for more information or contact the Planning Division at 650-802-4263.

Summary of New State Requirements:

Fire Requirements
ADUs within EXISTING SPACES Such as Primary Dwelling, Garage, Pool House, Etc.
Approval Process