Frequently Asked Questions

ADUs are allowed on any single-family residential, multi-family-residential and mixed-use zoned property where an existing single-family dwelling or multi-family dwelling has been established or a new single-family dwelling or multi-family dwelling is being proposed. 

The zoning districts which allow ADUs are R-1, R-2, R-3, R-4, P-D where residential use is allowed and Specific Plan areas where residential use is allowed. 

An Accessory Dwelling Unit is different from an Accessory Building.  An Accessory Building, or structure, includes sheds, tool sheds, workshops, and garden sheds. SBMC 12.84.140.

A Junior ADU (JADU) is permitted under Government Code Section 65852.22. A JADU is a type of an ADU which is converted from an existing living area and located entirely within the existing residence.  The maximum size of a JADU shall not exceed 500 s.f. A JADU shall have an efficiency kitchen while the bathroom can be independent or can be shared with the primary dwelling.  A JADU is allowed in addition to a detached, new construction ADU in all zoning districts allowed for ADUs. A JADU requires owner occupancy of the primary dwelling.

Each single-family residential property is allowed one new construction ADU in addition to a JADU. Each multi-family residential property is allowed up to two detached ADU units plus multiple converted ADUs, up to 25% of existing units that are created within any existing non-livable spaces (storage, equipment rooms, basement or passageways).

ADU statute limits the size of an attached ADU to 50% of the size of the existing primary dwelling (Gov. Code Section 65852.2(a)(1)(D)(iv)). The local agency is generally required to allow an ADU of at least 850 sq. ft, or 1000 sq. ft. if it contains more than one bedroom. In a situation where the local agency’s development standards, as noted in an adopted ADU ordinance, constrain the area for an ADU, it could be limited to no less than 800 sq.ft. (Gov. Code Section 65852.2(c)(2)(B) & (C)).

There are no setback requirements for any converted ADUs. For newly created ADUs, they must comply with the front setback requirement of the underlying zoning district and four feet minimum side and rear setbacks.

One additional parking space is required for each ADU unless it is within a half-mile walking distance from public transit, located within the architecturally and historically significant historic district, part of proposed or existing primary residence or an accessory structure, when on-street parking permits are required but not offered to the occupant of an ADU and when car share vehicles is located with one block of the ADU. Tandem parking is allowed. There is no replacement parking requirement for any ADU that is converted from an existing parking structure (garage or carport).

Until January 1, 2025, there is no owner occupancy deed restriction requirement imposed on any ADU.  However, owner occupancy of the primary dwelling is required for any new JADU.

Development Impact Fees are not required for any new ADUs up to 750 square feet in size. For ADUs that are more than 750 square feet in size, impact fees shall be calculated proportionally to the floor area of the main house. Connection and capacity fees should also be charged for detached ADUs only and should be calculated in proportion to the size of the unit or the total number of fixtures. ADU can only be considered a new residential use for the new utility service fee if it is constructed in conjunction with a new primary dwelling unit.

Until January 1, 2030, any code enforcement related correction pertaining to the creation of an ADU can be delayed up to five years, based on the owner’s request, for any ADU that was built before January 1, 2020.