Before starting designing your ADU here the California zoning guidelines to follow in order to determine what type and size will maximize the potential for your property:
Number of ADUs allowed:
No more than one accessory dwelling unit is permitted on any lot. An accessory dwelling unit shall not be permitted on a lot where a habitable accessory structure, excluding a pool house, already exists.
Types of ADUs allowed:
Attached, detached and conversions of existing space are permitted.
There is no minimum lot size for an ADU so long as a legal Single-Family Residence exists on the property.
ADU Size Requirements: 1.) An accessory dwelling unit shall have a minimum area of 150 square feet, including one habitable room with a minimum area of 70 square feet. 2.) The maximum floor area for an accessory dwelling unit shall be 1,200 square feet, except when: (a) For attached accessory dwelling units, the additional floor area shall not exceed 50 percent of the primary habitable area at the time of application submittal, with a maximum increase in floor area of 1,200 square feet. (b) Within a Hillside Management Area, the additional floor area for an attached or detached accessory dwelling unit shall not exceed 50 percent of the primary habitable area at the time of application submittal, with a maximum floor area of 800 square feet.
Distance of separation of the ADU from primary dwelling. The distance between the detached accessory dwelling unit and the primary dwelling shall be as follows:
(a.) A minimum of feet ; and, (b.) In Hillside Management Areas, a maximum of feet, unless the accessory dwelling unit is created entirely within the existing space of an accessory structure. Required Yards.
The minimum side and rear yard depths of an accessory dwelling unit shall be as follows:
- For accessory dwelling units created entirely within the existing space of a single-family primary dwelling or accessory structure, no yards are required.
- For accessory dwelling units not created entirely within the existing space of a single-family primary dwelling or accessory structure, the yards for the accessory dwelling unit shall be five feet.
- Accessory dwelling units shall not encroach into the required front yard of the primary dwelling.
A.) When ADU Parking Is Required:
- One bedroom: 1 parking space
- Two or more bedrooms: 2 parking spaces
- The proposed ADU is not entirely contained within the existing space of an existing detached garage or other accessory structure.
- An addition is proposed to an existing accessory structure that is converted into an ADU.
- The proposed ADU is not entirely contained within the existing space of the existing Single Family Residence.
- A garage, carport, covered parking structure is demolished or rendered unusable in conjunction with the construction of the ADU, any parking spaces required for the 7.) ADU or primary dwelling may be provided as covered, uncovered, tandem spaces on an existing driveway, or by the use of mechanical parking lifts (per Building and Safety).
B.) When ADU Parking Is Not Required:
- The ADU is entirely contained within an existing space of a primary dwelling or existing legal accessory structure (garage, guest house, rec room, etc.), and where no floor area expansion is proposed.
- The ADU is located within ½ mile of public transit (i.e. bus stop, bike share station, train station). Check current transit map for locations. Site plan should depict the location and distance of a public transit stop.
- On-street parking permits are required but not offered to the ADU occupant.
- There is a car share vehicle located within one block (includes both sides of the street) of the ADU.
State standards require that an ADU shall not require fire sprinklers unless they are already installed in the primary dwelling. If the primary home has fire sprinklers existing, the ADU may require them.
Shape, materials and style:
The ADU must be visually compatible with the primary home and the surrounding neighborhood. This typically means that the ADU should be designed to have similar exterior colors, materials, roof pitch and massing to the primary home.
Height. The maximum height of an accessory dwelling unit shall be:
Max 25 foot height, except for when:
- For accessory dwelling units created entirely within the existing space of an accessory structure, the maximum height shall be equal to the maximum height of the accessory structure.
- For accessory dwelling units created entirely within the existing space of a single-family primary residence, the maximum height shall be equal to the height of the primary residence. (3) For accessory dwelling units not described in subsection (1) or (2) above, and within 200 feet of an adopted state Scenic Highway, the maximum height shall be 18 feet.
Community Standards District regulations shall apply as specified in Section 22.78.XX.B.2 (accessory dwelling units). Permitted Areas. accessory dwelling units are permitted where single-family residential uses are permitted with a Ministerial Site Plan Review (Chapter 22.186). D. Application Requirements. An approved Ministerial Site Plan Review (Chapter 22.186) is required to establish an accessory dwelling unit that is located in a permitted area as provided in Subsection C, above. E. Timeline for Approval: Complete applications for an accessory dwelling unit shall be approved or denied by the Department within 120 days.
Number of Bedrooms: Not specified by State Standards.
The owner of the property is no longer required to occupy the primary home or the ADU. Release of covenant. The County of Los Angeles releases its interest in any
covenant for an accessory dwelling unit which required owner-occupancy in perpetuity of either the primary single-family residence or the accessory dwelling unit that is located on the same lot, recorded in the office of the county recorder, running with the land for the benefit of the County of Los Angeles. An accessory dwelling unit shall not be separately sold from the primary single family residence on the same lot. An accessory dwelling unit may be used as a rental unit. An accessory dwelling unit may be developed on a lot that is owned by the owner of the primary dwelling and that either: (a.) Contains at least one legally established detached single-family residence; or
(b.) Will have at least one new detached single-family residence permitted concurrently with the accessory dwelling.
No more than one accessory dwelling unit is allowed on a property. An accessory dwelling unit shall not be used for a home-based occupation if there is a home-based occupation in the primary dwelling.
Local health officer approval where a private sewage disposal system is being used, if required. (State requirements)
For coastal areas, please refer to the applicable Local Coastal Program at http://planning.lacounty.gov/coastal.
The property is zoned R-1, R-2, R-3, R-4, R-A, A-1 and A-2, or another zone where a single-family residence (SFR) is allowed by right with a plot plan (ministerial review).
An ADU is not counted towards lot coverage, GSA or FAR. However, non-ADU structures shall adhere to the maximum zone or CSD lot coverage requirement.
At the time of application submittal, an accessory dwelling unit in a Very High Fire Hazard Severity Zone shall be located on a lot that fronts a vehicle roadway that is 24 feet in unobstructed width from the property line to the nearest publicly-maintained street.
Minimum Space Requirements
Living/bedroom area: 70 sq. ft.
Bathroom (Must include toilet, lavatory and bathtub or shower): 30 sq. ft.
Kitchen/closets/hallways (Kitchen area with sink, stove, and refrigerator): 50 sq. ft.
Single-Family Residence Standards. An accessory dwelling unit shall comply with Section 22.140.580 (Single-Family Residences), except Section 22.140.580.B (Minimum Building Width) and Section 22.140.580.C (Minimum Floor Area) shall be superseded by this Subsection G.