Build an ADU in Los Angeles, California

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Los Angeles is located in Los Angeles County in California. Los Angeles has a
total population of 3792621 over a land mass of 468.67 Square Miles. When it
comes to ADUs, the city allows for 1-2 ADUs on a given property, and a square
footage of Up to 1,200 sf

Number of ADUs Allowed


Size of ADU Allowed

Up to 1,200 sf

Types of ADUs Allowed

Detached, Junior, Attached

Permit Cost

Coming Soon

Number of ADUs allowed

Except as otherwise permitted by this subdivision, one ADU is permitted per
residential lot. Single family residential lots may be permitted up to one ADU
and one JADU according to state AB-68.

Property Requirements

ADUs: The Floor Area for a detached ADU shall not exceed 1,200 square feet. If
there is an existing primary dwelling, the Floor Area of an attached ADU may not
exceed 50 percent of the existing primary dwelling. No other minimum or maximum
size for an ADU, including size based upon a percentage of the proposed or
existing primary dwelling, or limits on lot coverage, floor area ratio, open
space, and minimum lot size, shall apply for either attached or detached
dwellings that does not permit at least an 800 square foot ADU that is single
story and meets required setbacks. JADUs: A unit that is no more than 500 square
feet in size and contained entirely within a single-family residence. Movable
Tiny Houses: No smaller than 150 and no larger than 430 square feet as measured
within the exterior faces of the exterior walls.

Types of ADUs Allowed

Attached ADU

An attached ADU is one that is attached to your house. Also know as Addition ADUs or “bump-out ADUs. These types of ADUs can be accessed from the primary house with a door in the connection point, but also can be independent of the main home.

Detached ADU

A detached ADU is not connected to your primary house. The dwelling needs to be within your property setbacks and allowable building size (both height and square footage).

Junior ADU

Junior Accessory Dwelling Units (JADUs) are named this way because they are small (up to 500 square feet).

In California, the recent state bills AB68 and AB 881 permits both an ADU and a Junior ADU (JADU) on the same lot with a proposed or existing single-family dwelling. This means you can have two units on your lot: ADU, and JADU.

Property Requirements

According to state law, the owner of the property is not required to occupy the
primary home or the ADU.
Number of ADUs Allowed
Except as otherwise permitted by this subdivision, one ADU is permitted per
residential lot. Single family residential lots may be permitted up to one ADU
and one JADU according to state AB-68.
ADU Size
There is no minimum lot size for an ADU so long as a legal Single Family or
Multi-Family Residence exists on the property.
Parking Requirements: (i) ADU Parking. One parking space is required for an ADU,
except that no parking is required for an ADU that is: a. Located within
one-half mile walking distance of a public transit. For this purpose, public
transit means a location, including, but not limited to, a bus stop or train
station, where the public may access buses, trains, subways, and other forms of
transportation that charge set fares, run on fixed routes, and are available to
the public; or b. Located within one block of a designated pickup and drop-off
location of a car share vehicle; or c. Located in an architecturally and
historically significant district listed in or formally determined eligible for
listing in the National Register of Historic Places or California Register of
Historical Resources or located in any City Historic Preservation Overlay Zone;
or d. Part of the proposed or existing primary residence or an accessory
structure. (ii) ADU Parking Location. ADU parking is allowed in any yard area or
passageway. When located in a required front yard, the parking must be located
on an existing driveway. Parking may be provided through tandem parking where
two or more automobiles are parked on a driveway or in any other location on a
lot, lined up behind one another. Driveway access areas located in the required
front yard shall not be expanded to provide required parking. Other objective
parking and driveway standards in the LAMC apply, including those found in
Sections 12.21 A.5 and 12.21 A.6. However, Section 12.21 A.6(d) of this Code
shall not apply to parking required for an ADU. (iii) Replacement Parking. No
replacement parking shall be required when a garage, carport or covered parking
structure is demolished in conjunction with the construction of an ADU or
converted to an ADU.
Height. The height of an accessory dwelling unit shall be: A.) At least 16 feet,
except for when: 1.) The height of the zoning district allows for greater
height. 2.) For accessory dwelling unit is created entirely within the existing
space of an existing, legal accessory structure, the maximum height shall be
equal to the maximum height of the accessory structure. 3.) For accessory
dwelling unit is 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.
Fire Safety
The ADU shall not require fire sprinklers unless they are already installed in
the primary dwelling or the property is located in a special fire or hillside
overlay, in which case, they may be required. Movable Tiny Houses are not
required to have sprinklers, but shall follow the ANSI A119.5 or NFPA 1192
standards relating to health, fire and life-safety.
Utility Connections
ADUs shall not require utility connections that are separate from the primary
residence. ADUs located where a private sewage disposal system is being used,
shall require approval by the local health officer. ADUs are required to comply
with all applicable Building and Residential Codes for the proposed use. Movable
Tiny Houses shall be connected to water, sewer and electric utilities in
compliance with applicable codes.
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.
Movable Tiny Houses shall have the following design elements: (i) Cladding and
Trim. Materials used on the exterior of a moveable tiny house shall exclude
single piece composite, laminates, or interlocked metal sheathing. (ii) Windows
and Doors. Windows shall be at least double pane glass and labelled for building
use, and shall include exterior trim. Windows and doors shall not have radius
corners. (iii) Roofing. Roofs shall have a minimum of a 12:2 pitch for greater
than 50 percent of the roof area, and shall not be composed of wooden shingles.
(iv) Extensions. All exterior walls and roof of a moveable any tiny house used
as an ADU shall be fixed with no slide-outs, tip-outs, nor other forms of
mechanically articulating room area extensions. + Is licensed and registered
with the California Department of Motor Vehicles; + Meets the American National
Standards Institute (ANSI) 119.5 requirements or the National Fire Protection
Association (NFPA) 1192 standards, and is certified for ANSI or NFPA compliance;
+ Is no larger than allowed by California State Law for movement on public
highways; and + Cannot move under its own power; + When sited on a lot, the
undercarriage (wheels, axles, tongue and hitch) shall be hidden from view.
Set backs
No additional setbacks shall be required for an existing living area or
accessory structure, or a structure constructed in the same location and to the
same dimensions as an existing structure, converted to an ADU or portion of an
ADU. New construction ADUs require 4-foot side and rear yard setbacks.

Design Review

State Standards don't require any additional design review.

Next Steps

To get started on your ADU, here are some first steps.

Call Your City

Search Google for your city’s contact number. eg “City of {Phoenix} Residential Permits Contact Number”

You can call the main line and get directed to the permitting department.

Ask these questions...

1) Can I put a secondary home on my lot (Accessory Dwelling Unit)?
2) What are my livable setbacks, and ADU size regulations?
3) Can I put a prefabricated guest house on my property?

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