Prefab ADU in LA County | Backyard Home with LiveLarge

LA County ADU Standards

Prefab ADU in Los Angeles County

What is an Accessory Dwelling Unit (ADU)?

An Accessory Dwelling Unit (ADU) is an independent, self-contained residential unit located on the same lot as a primary home. It provides additional living space, potential rental income, or a solution for multi-generational housing.

A Prefab ADU is a permanent, factory-built structure that complies with local zoning and building codes, making it perfect for long-term occupancy.

Tiny homes are frequently mistaken for prefab ADUs, but there are important differences. Tiny homes are small, mobile units built on wheels, whereas prefab ADUs are stationary and constructed for durability and permanence. While tiny homes can function as ADUs, they often face more stringent zoning restrictions due to their mobility.

Planning to Build an ADU in Los Angeles County?

With recent updates to ADU regulations, Los Angeles County has experienced an increase in ADU construction. If you’re considering building an ADU in Los Angeles County, LiveLarge is here to help you navigate the essential requirements, ensuring your project goes smoothly from start to finish.

Types of ADUs

Junior ADU (JADU): Located within an existing or proposed space of a single-family residence (SFR).
Attached ADUs: Created by converting part of an existing SFR and/or through new construction.
Detached ADUs: Created by converting a detached accessory structure and/or through new construction.

Maximum ADU Size

JADU: 500 sq. ft.
Attached ADUs: 50% of the existing SFR’s square footage or 1,200 sq. ft., whichever is less, at least 800 sq. ft. ADU is allowed.
Detached ADUs: 1,200 sq. ft.

Height Regulations

25 feet or as specified by CSD/Specific Plan, whichever is less.

Setback Requirements

Front: Per Title 22 regulations
Sides & Rear: 4 feet
Distance from Main House: 6 feet

Parking Requirements:

General Parking Guidelines

If a garage, carport, or covered parking structure is demolished or converted into an ADU, no replacement parking is required for the existing dwelling or ADU.
If the parking structure is not converted into an ADU, covered parking must still be provided for the existing dwelling(s).
Parking spaces, when required, must be 8.5 ft. x 18 ft.
Compact parking spaces are not allowed.
If a parking structure is not being converted into an ADU, existing SFR and MFR parking requirements still apply.
26 feet of clear vehicle backup space must be provided.
Vehicles may not be parked in required front yards (anywhere between the existing dwelling and the street) or corner side yards, except on designated driveways.

No Parking is Required for:

JADUs.
ADUs located outside a Very High Fire Hazard Severity Zone (VHFHSZ).

ADUs Located Within a VHFHSZ Require One Uncovered Parking Space, Unless:

The ADU has no bedroom.
The ADU is detached from an existing SFR, with:
- A maximum floor area of 800 sq. ft.
- A maximum height of 16 ft.
The ADU is detached from an existing MFR, with:
- A maximum height of 16 ft.
- Minimum rear and side yard setbacks of 4 feet.
The ADU is entirely contained within an existing space of a primary residence or legal accessory structure (e.g., garage, guesthouse, recreation room) without floor area expansion.
The ADU is located within ½ mile of public transit (bus stop, bike-share station, train station).
The ADU is in an architecturally or historically significant historic district.
On-street parking permits are required but not offered to ADU occupants.
A car-share vehicle is located within one block of the ADU (both sides of the street).

For more information, contact Los Angeles County Planning at (213) 974-6411 or via email at info@planning.lacounty.gov.

Let LiveLarge Home be your trusted partner for your ADU journey in Los Angeles County. With our expertise in design, construction, and pre-approved plans, we ensure your project aligns with local standards and maximizes your property’s potential.

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