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Local ADU Rules

City of Cotati

Last Updated September 13, 2024

ADU Contact:

Cotati Community Development Department, 707-665-3635, planner@cotaticity.org

Disclaimer: standards and process may vary. Consultation with City staff is recommended before starting any project.

Standards	Details
Zones allowed	Residential and mixed-use zones: RR, RVL, NL, NM, NU, CE, CG, CD, HC, LP, NG, CA
Lot Restrictions	Must have an existing or proposed single-family or multifamily dwelling.
Minimum Lot Size	None
Min/Max ADU Size	The minimum ADU size is the minimum size permitted by the CA Building Code. On lots of less than ½ acre, the maximum size is 850 square feet for studio or 1 bedroom ADUs and 1,000 square feet for 2+ bedroom ADUs. Exceptions may be approved through a discretionary design review process. On lots of ½ acre or more, the maximum size is 1,200 square feet.
ADU Building Height	Detached ADUs may be up to 16 feet in height, or 18 feet in the following situations: When within ½ mile of the SMART station; If accessory to a multifamily, multistory residence(s); or When constructed over an existing garage (height limit applies to entire structure). Attached ADUs may be up to 25 feet in height. Any ADU (or portion of an attached ADU) that meets the setbacks required by the zoning for the primary residence(s) may exceed these height limits, up to the maximum building height allowed by the zoning for the primary residence (typically 28 feet in residential zones).
Setbacks	4 feet from the rear and side property lines, if: The ADU is 16 feet or less in height; The ADU is detached,18 feet or less in height, and located within ½ mile of the SMART station or accessory to a multifamily, multistory dwelling; or The ADU is attached to the primary residence(s) and 25 feet or less in height. 5 feet from the rear and side property lines if the ADU is constructed over an existing garage and the entire structure is 18 feet or less in height. If the ADU is greater than the height limits described above, the setbacks of the underlying zoning district apply. No setbacks are required for conversions of legally existing structures to ADUs.
Parking Requirements	One space unless the site is located within ½ mile of public transit or the ADU is located within an existing or proposed residence or accessory structure. Other parking exemptions may also apply.
Owner Occupancy	Not required
Sample fees from recent permits	620 sqft Detached ADU New construction $3,022.43 School fee of $3.79 per/sqft not included *Fees are specific to each project and will vary. Fees change regularly. These are provided as examples only.
Other requirements	ADUs are treated like residential additions and only building and school fees (if greater than 750 sqft) are required. ADUs must tap into existing sewer and water connections serving the primary residence so no new service laterals or meters are installed. An ADU may be required to have fire sprinklers if they are required in the primary dwelling unit. However, installation of fire sprinklers in an ADU will not trigger a requirement for fire sprinklers in the primary unit. Short-term rentals (<30 days) of ADUs are not permitted.
Process	Ministerial; Building Permit.
Exceptions	None

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