ADU Zoning and Requirements in Los Angeles: What Homeowners Need to Know in 2026

What Is an ADU in Los Angeles?

An accessory dwelling unit (ADU) is a secondary, self-contained home on a lot that already has, or will have, a primary residence. ADUs are also called granny flats, in-law units, or backyard cottages. Los Angeles recognizes several types:

Can I Build an ADU on My Property in Los Angeles?

Usually yes. Los Angeles allows ADUs on lots zoned for residential use that already have, or are proposed to have, a single-family or multifamily home. State ADU law does not set a minimum lot size, so the old rule of thumb that you need at least 2,000 square feet of lot is not a requirement we apply. What limits you is the buildable area left after setbacks and floor-area rules.

Whether your lot qualifies depends on four checks:

California State Law vs. Los Angeles Rules

A Los Angeles ADU can be permitted under State ADU law, under the City ordinance, or under a mix of both. The city’s own zoning memo, ZA Memo 143, summarizes how the two fit together.

Topic	State law (minimum standard)	City of Los Angeles ordinance
Detached size	Up to 800 sq ft	Up to 1,200 sq ft, subject to floor-area and lot limits
Attached size	Varies by case	Generally up to 50% of the existing dwelling, with exceptions for smaller units
JADU	Up to 500 sq ft, inside the home	Up to 500 sq ft, inside a single-family home
Height (detached)	16 ft, or 18 ft within a half mile of qualifying transit; up to 20 ft if the roof pitch matches the main house	Up to two stories, within the zone’s height limit
Rear and side setbacks	4 ft	4 ft for new construction
Parking	None required	Generally one space, with many exceptions
Number per lot (single-family)	One detached ADU, plus a JADU	One ADU per lot under the ordinance
Approval timeline	60 days from a complete application	Same: 60 days

Because the options differ, the best path for your property is a design decision, not just a code check. That is why we start every project with the lot, not the floor plan.

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ADU Requirements in Los Angeles

Size limits

Size limits depend on the type of ADU and the path you choose:

• Detached, state-law path: up to 800 square feet.
• Detached, city-ordinance path: up to 1,200 square feet, unless other zoning limits apply.
• Attached: generally capped at 50% of the existing dwelling. An attached ADU under 850 square feet (or under 1,000 square feet with more than one bedroom) may exceed that limit.
• JADU: up to 500 square feet, within a single-family home.

The lot’s total floor-area and lot-coverage limits still matter on the city path, which is why a larger lot does not automatically allow a larger ADU.

Height and stories

For a detached ADU on a single-family lot under state law, the standard limit is 16 feet. That rises to 18 feet within a half mile of qualifying transit, and an additional 2 feet (20 feet total) is allowed if the roof pitch aligns with the main dwelling. Under the city ordinance, a detached ADU can have up to two stories, within the zone’s height limit. An attached ADU is held to the zone’s height limit for a new building or addition, or 25 feet, whichever is lower.

Setbacks

New detached and attached ADUs need 4-foot side and rear setbacks. If you convert an existing structure, such as a garage, no added setbacks are required, and if the existing side setback is under 4 feet, the lesser setback applies. Front setbacks cannot prevent an 800 square foot ADU elsewhere on the lot.

Parking

State-law ADUs and JADUs require no parking. Under the city ordinance, an ADU generally needs one space unless an exception applies, such as:

• The property is within a half mile of a bus or rail stop.
• A car-share location is within one block.
• The property is within a historic district.
• The ADU is fully inside the existing or proposed home or an existing accessory structure.

Replacement parking is not required when a garage or carport is removed to create an ADU.

Fees

Permit and plan-check fees are set by Los Angeles based on project valuation, not a flat ADU fee, so your design and permit set drives the number. State law also limits impact fees. According to California’s Department of Housing and Community Development (HCD) ADU Handbook (updated March 2026), ADUs of 750 square feet or less are exempt from impact fees. Ask us for a project-specific estimate once the scope is defined.

How many ADUs can you build?

Under the city ordinance, you can build one ADU per lot. State law is broader: on a single-family lot it requires cities to allow one detached ADU plus a JADU, and on an existing multifamily lot, up to eight detached ADUs (not exceeding the number of existing units). Recent state legislation has also changed how combinations of ADUs are counted, so confirm with the city or with us before you plan more than one unit.

Owner occupancy and rentals

California law removed the authority of local agencies to require owner occupancy for an ADU on a lot with a single-family home. Local agencies may require rentals of 30 days or longer. JADUs have different owner-occupancy rules, which have been changing, so confirm the current requirement before you design one.

Special Zones That Change the Rules in Los Angeles

Most of the surprises in Los Angeles come from the location of the lot, not the unit itself.

Hillside lots in a Very High Fire Hazard Severity Zone. The city ordinance prohibits ADUs on any lot located in both a Very High Fire Hazard Severity Zone and a Hillside Area, subject to listed exceptions. According to ZA Memo 143, this restriction is not enforced on State ADU types, which means the state-law path may still be open on a lot that the city ordinance would block. Fire sprinklers cannot be required for an ADU if the primary residence did not require them.

Coastal Zone. State ADU law does not override the California Coastal Act. In the Coastal Zone, an ADU project requires a Coastal Development Permit, which is a separate City Planning filing and can involve public notice or a hearing for demolition, conversion, new construction, or subdivision. Parking may also be required case by case.

Historic districts. Inside a historic district, the parking exception above applies. Demolishing a detached garage for an ADU requires notice and a placard in a historic district, such as an HPOZ or a state or national register district.

If your home is in a hillside, coastal, or historic area, tell us before you commit to a design. It changes which path is available.

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How to Check Your Property’s Zoning

The ADU Permit Process in Los Angeles

A Los Angeles ADU permit follows a predictable sequence:

1. Site and zoning review. Confirm the lot, the path (state, city, or both), and any special-zone rules.
2. Design and drawings. Prepare floor plans, a site plan, and the structural and energy documents the city requires. As-built plans are needed if you are converting an existing structure.
3. Submit to the Los Angeles Department of Building and Safety (LADBS) with the complete application and fees.
4. Plan check and corrections. If the city requests changes, you respond with revised drawings. See our plan corrections service.
5. Approval and permit issuance. By law, the city must approve or deny a complete ADU application within 60 days, and the application is deemed approved if the city takes no action.
6. Construction and inspections by your contractor.

Standard plans

LADBS runs an ADU Standard Plan Program with plans pre-approved for compliance with the Building, Residential, and Green Codes. After you select a plan, LADBS checks site-specific factors such as zoning compliance and foundation requirements, and using a standard plan shortens plan check. The program includes one free City-owned plan and many privately owned plans sold by their designers. Not every plan fits every lot, and a custom design is often the better choice for an irregular site or a larger unit.

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