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Local ADU Rules

San Carlos

Last Updated November 4, 2024

ADU Contact:

Deanna Skaggs – dskaggs@cityofsancarlos.org; planning@cityofsancarlos.org

Standards	Details
Zones allowed	All districts where residential is allowed: RS, RM, and MU
Lot Restrictions	Floor area ratio, lot coverage, height, natural state requirements for the underlying zone
Minimum Lot Size	0
Min/Max ADU Size	One bedroom or less: 850 square feet Two+ bedrooms: 1000 square feet Conversion of existing legally established detached structures: None JADU: 500 square feet *50% of main home floor area, unless under 800 square feet (state law allows an ADU up to 800 square feet on every property)
ADU Building Height	Detached ADU: 18 + 2 feet to match the main building roof pitch Detached ADU with multistory, multifamily dwelling: 18 feet Detached ADU over or under detached garage: 20 feet Attached second story: determined by base zoning
Setbacks	First floor attached and detached: Side and rear – 4 feet, Front: setbacks determined by base zoning district The second floor is attached: determined by the base zoning district The second floor is attached on reversed corner lots: rear – 5 feet
Parking Requirements	JADUs: Any parking displaced by the construction of a JADU, including full or partial conversion of an existing garage, shall be replaced ADUs: One spot may be required (tandem allowed). No parking is required if ADU involves garage conversion or is: ½ mile walking distance from public transit, in a historic district, or one block from a car-share vehicle; or when on-street parking permits are required but not offered to ADU occupants
Owner Occupancy	JADUs: Required ADUs built recently (2020-2024): Not required *Where a lot contains both an accessory dwelling unit and a junior accessory dwelling unit, either the single-unit dwelling or the junior accessory dwelling unit shall be owner-occupied
Sample fees from recent permits	ADU (500 sf, garage conversion): ~$7,500 No impact fees are required for JADU/ADUs smaller than 750 square feet
Other requirements	No short-term rentals allowed ADUs must conform to all development standards in the Zoning District in which they are proposed. All construction near a creek is subject to the requirements of Chapter 18.14 Stream Overlay District, which requires a 25′ setback from the creek top-of-bank. The setback requirement is waived to allow ADUs of at least 800 square feet. A permit may be required for protected tree removals. JADU: Architectural design, materials, and details should be the same as those of the primary dwelling. No detached JADUs are allowed. Shall be consistent with the objective design standards of the underlying zoning district. Recordation of a deed restriction is required for JADUs
Process	Applicants shall submit the ADU/JADU building permit application to the San Carlos Building Division. Once received by the Building, the submittal is routed to planning and other pertinent departments for plan-check review. After all rounds of reviews are completed and all comments are resolved, the building permit is ready for approval and issuance. For a smoother process, applicants are encouraged to meet with the San Carlos Planning Division before submitting for a building permit.
Exceptions	ADUs smaller and up to 800 square feet are exempt from but not limited to floor area ratio (FAR), natural state, creek setback, and lot coverage requirements

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