Accessory Dwelling Unit

2020 ADU & JADU Development Standards

What is an ADU?

In 2016, the State Legislature approved two amendments to State Law which required local agencies to ministerially consider accessory dwelling unit (or ADU) applications in residential zones. The legislation consists of Assembly Bill 2299 and Senate Bill 1069, which together amended California Government Code Section 65852.2. This legislation is the result of a statewide housing crisis, rising housing costs, and a shortage of affordable housing options.

In 2019, the State Legislature approved amendments to the ADU law (AB68) that took effect on January 1, 2020. The new ADU laws relaxes many of the regulations that cities were able to impose on ADUs and Junior ADUs (JADU).

An ADU is an attached or detached residential dwelling unit which provides complete independent living facilities for one or more persons, and includes permanent provisions for living, sleeping, eating, cooking (i.e., stove, refrigerator, and sink), and sanitation (i.e., bathroom, with shower or bathtub) on the same parcel where an existing single-family or multi-family dwelling is situated. Accessory Dwelling Units (ADUs) have been known by many names: granny flats, in-law units, backyard cottages, secondary units and more. No matter what you call them, ADUs are an innovative, affordable, effective option for adding much-needed housing in California. 

 

What kind of ADUs are there?

There are two (2) types of ADUs - an ADU and a JADU. There are three (3) kinds of ADU construction, a conversion of an existing accessory structure or portion of a dwelling unit, a detached ADU, and an attached ADU. ADUs can be attached or detached (free standing) to an existing single family or multi-family home. New ADUs have to adhere to all development standards of the state law. When a portion of the existing single-family or multi-family home or an existing accessory structure is converted into an ADU, it is exempt from meeting certain development standards. All residential lots can have one (1) ADU and one (1) JADU. 

Single-family ADU Development Standards

ADUs are permitted single-family residential zoned properties (R-1). All ADUs shall be constructed with independent access separate from the main residence entrance. All ADUs shall have a living/sleeping area, a kitchen or kitchenette (i.e., stove or hotplate, refrigerator, and sink), and a bathroom includes a shower or bathtub. ADUs are no longer subject to Lot Coverage and Floor Area Ratios of the city’s zoning designation. The following are single-family ADU development standards:

Detached:

Maximum of two (2) stories or 25 feet.

Not to exceed 1,200 square.

ADU shall match the architectural design of the existing or proposed main dwelling.

Attached:

Maximum of two (2) stories or 25 feet.

Cannot exceed 50% of the existing main dwelling unit.

ADU shall match the architectural design of the existing or proposed main dwelling.

Setbacks:

ADUs shall adhere to the state’s setbacks of four (4) feet from the side and rear yard and must remain 6 feet from the existing main dwelling. Existing accessory structures and single family homes that are converted into ADUs are exempt from meeting the required setbacks however, any expansion shall meet the four (4) foot side and rear yard setback, as pursuant to Government Code Section 65852.2.

 

Parking:

All new ADUs will be required to provide one (1) additional parking space, cover or uncovered if the proposed ADU is not within a one-half (.5) mile radius of public transit station (bus stops included). However, for accessory structures or a portion of the existing residence that is converted into an ADU, no additional parking is required. An ADU cannot have direct access to a garage if the proposed or existing garage has less than three (3) spaces.

 

Junior ADU Development Standards

Junior Accessory Dwelling Units (JADUs) are a very small living units created within an existing dwelling or accessory structure. The JADU must have a living/sleeping area, and a kitchen or kitchenette (i.e., stove or hotplate, refrigerator, and sink). A bathroom is not required, however if a bathroom is not provided, the JADU shall have a direct access into an existing dwelling unit. A JADU cannot exceed a total of 500 square feet and any expansion of the existing dwelling or accessory structure to accommodate the JADU shall not exceed 150 square feet.

 

Setbacks:

JADUs shall adhere to the state’s setbacks of four (4) feet from the side and rear yard. Existing accessory structures and single family homes that are converted into ADUs are exempt from meeting the required setbacks as pursuant to Government Code Section 65852.2.

 

Parking:

Parking is not required for JADUs, however, an ADU cannot have direct access to a garage if the proposed or existing garage has less than three (3) spaces.

 

Multi-family Lots ADU Development Standards

ADUs are permitted on multi-family  zoned properties (R-2 & R-3). All ADUs shall be constructed with independent access separate from the main residence entrance. All ADUs shall have a living/sleeping area, a kitchen or kitchenette (i.e., stove or hotplate, refrigerator, and sink), and a bathroom includes a shower or bathtub. ADUs are no longer subject to Lot Coverage and Floor Area Ratios of the city’s zoning designation.

Detached:

Not more than two accessory dwelling units that are located on a lot that has an existing multifamily dwelling, but are detached from that multifamily dwelling and are subject to a height limit of 16 feet and four-foot rear yard and side setbacks.

Conversion within:

Multiple accessory dwelling units within the portions of existing multifamily dwelling structures that are not used as livable space, including, but not limited to, storage rooms, boiler rooms, passageways, attics, basements, or garages, if each unit complies with state building standards for dwellings.

At least one (1) accessory dwelling unit within an existing multifamily dwelling and shall allow up to 25 percent of the existing multifamily dwelling units.

 

Setbacks:

ADUs shall adhere to the state’s setbacks of four (4) feet from the side and rear yard. Existing accessory structures and portions of multi-family developments that are converted into ADUs are exempt from meeting the required setbacks as pursuant to Government Code Section 65852.2.

Parking:

All new ADUs will be required to provide one (1) additional parking space, cover or uncovered if the proposed ADU is not within a one-half (.5) mile radius of public transit station (bus stops included). However, for accessory structures or a portion of the existing residence that is converted into an ADU, no additional parking is required. An ADU cannot have direct access to a garage if the proposed or existing garage has less than three (3) spaces.

Application Process

An ADU requires a Building Permit which applicants will obtain by submitting for Plan Check with the Building Division. The Building Division will then route plans to each of the applicable Divisions for review. Upon receiving departmental approvals, the applicant will then be issued a Building Permit.

 

NOTE:

Prior to submitting an application to the Planning Division, a review shall be conducted by staff to ensure that your proposed project will meet all ADU Standards with the City of Alhambra and the State of California. If you have any questions or concerns regarding the ADU or JADU Development Standards or the ADU/JADU application process, please contact the Planning Division at (626) 570-5034.

Click here for the Accessory Dwelling Unit State Assembly Bill 68.

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