Los Angeles County

Get Started   Design Yours

About – COUNTY OF LOS ANGELES

ADU Builder in Los Angeles County

Los Angeles County is one of the strongest ADU markets in California — high rents, flexible zoning, and county-level permitting that moves faster than most incorporated cities. Apex Homes specializes in building ADUs here, managing everything from design and permits to construction so you’re not coordinating it yourself. If you’re ready to build, we’ll tell you exactly what’s possible on your lot for free. 

Los Angeles County ADU Regulations

Los Angeles County follows California state ADU law while applying its own local standards for both single-family and multi-family properties.

Single-family lots (R-1)

  • One detached or attached ADU + one Junior ADU (JADU) permitted
    • Detached ADUs: up to 1,200 sq ft; attached 
    • ADUs: up to 50% of the primary dwelling’s size
    • JADUs capped at 500 sq ft, located within the primary dwelling
  • Side and rear setbacks: 4 ft minimum
  • Unit separation: 6 ft for ADUs ≤800 sq ft; 10 ft (or attachment required) for ADUs >800 sq ft
  • Height: up to 16 ft; up to 18 ft if within ½ mile of public transit

Multi-family lots (R-2+)

  • Up to 8 detached ADUs permitted, or attached ADUs equal to 25% of existing units — whichever is greater
  • Conversions of existing non-livable space (garages, storage) also permitted
  • Same setback and height requirements apply

Two-story ADUs are permitted up to the applicable zoning height limit, excluding basements. Front-yard placement is not permitted for detached ADUs.

Apex Homes handles zoning verification, setback calculations, and code compliance — included in your free feasibility study.

Build Your ADU in Los Angeles County

Start with ParcelZ. Enter your address and get instant eligibility, your buildable area, and matching floor plans. Free, no signup. Then our team takes it from there.

The Los Angeles County ADU Permitting Process

To obtain an ADU permit in Los Angeles County, homeowners should first confirm their property’s zoning and review the County’s ADU standards.

Free Feasibility Study

Apex checks your zoning, lot size, setbacks, and utility connections at no cost, before you commit to anything.

Select a Pre-Approved Plan

Choose from LA County-compatible ADU layouts. No custom design review required. Permits move faster and cost less.

Apex Submits Your Permit Package

We prepare and submit all site-specific documents (site plan, floor plans, elevations, structural details, Title 24) to the Los Angeles County Department of Public Works Building and Safety Division.

Permit Issued

Typically 2–4 months. LA County issues permits digitally, allowing construction to begin promptly. Apex manages all county follow-up and responds to plan-check comments.

Construction & Inspections

Apex builds your ADU and manages all county inspections. We deliver a finished, move-in ready unit, typically within 5 months of your feasibility study.

Check my Property Eligibility


 

Why Build an ADU in Los Angeles County?

Los Angeles County’s high housing demand and diverse neighborhoods make it an excellent place to invest in an ADU. Homeowners can generate steady rental income while adding long-term value to their property, creating a smart financial investment.

ADUs also provide flexible living options for families, allowing space for aging parents, adult children, or guests while maintaining privacy and independence. With careful planning, these units can enhance your property’s functionality without sacrificing style or comfort.

The county supports ADU development through clear regulations, flexible zoning, and streamlined permitting processes. Apex Homes guides homeowners through the entire process, from design to construction, making it simple to bring your ADU vision to life.

Book a free one-on-one consultation with our team to explore how an ADU can maximize your property’s potential in Los Angeles County.

 

Have questions? Contact Apex Homes Today

Our team knows Los Angeles County’s zoning, permits, and pricing inside out. Call us for a free, no-pressure conversation about your property. We’ll tell you exactly what’s possible.

Recent Apex Homes ADU Projects

A look at completed Apex Homes ADU builds across the Bay Area.

991 Sqft | 3B2B

991 Sqft | 3B2B


service includes:

DesignPermitBuildFinish Materials

A 991 sq ft 3-bed / 2-bath detached ADU in San Jose, fully condo-converted under AB 1033 and ready for separate sale — either the main house or the ADU can be acquired, financed, and resold on its own.

View more details
983 sqft 3B3B

983 sqft 3B3B


service includes:

DesignPermitBuildFinish Materials

Set on a corner lot in San Jose, this 983 sqft, two-story ADU is positioned at the rear of the property. It's a placement that lets a growing family live together today, and converts just as easily to a rental down the road.

View more details
749 sqft | 2B2B

749 sqft | 2B2B


service includes:

DesignPermitBuildFinish Materials

A 749 sq ft, 2-bed / 2-bath detached ADU in San Jose, built turnkey alongside a full remodel and ADU-title-conversion of the existing main house. The owner ends up with two independent rental units on a single 7,800 sq ft lot.

View more details
1200 sqft | 3B2B

1200 sqft | 3B2B


service includes:

DesignPermitBuildFinish Materials

A 1,200 sq ft, 3-bed / 2-bath detached ADU added to a duplex lot in central San Jose — taking the property from two income units to three, with the new ADU placed at the rear of a deep narrow lot and four mature trees preserved through construction.

View more details
view all projects

Apex Homes vs. Other Los Angeles County ADU Builders

Design-builders, general contractors, and prefab vendors each cover part of the job. Apex Homes covers all of it, in-house.

Apex
Homes
Other
Design-Builder
Other
Contractor
Other
Pre-Fab Vendor
Free Feasibility Study
Pre-Approved Design Options
Maybe
Full Permit Handling
Maybe
In-house Project Management
Maybe
Solar Installations Included
Maybe
Maybe
On-time, On-budget
Transparent Pricing
Move-In Ready Interior
Maybe
Maybe

Swipe to compare →

FAQs

Frequently asked questions

ADUs and JADUs smaller than 750 square feet are not subject to impact fees. For units 750 square feet or larger, fees are reduced and calculated proportionally based on the square footage of the primary dwelling or the average unit size.

In most cases, ADUs do not require a separate parking space, making it easier to add extra living space to your property.

If the main house does not have fire sprinklers, ADUs generally do not need them either.

No. Detached ADUs cannot be located in the front yard or in front of the primary residence.

Turn your Los Angeles County backyard into extra income or a home for family, without moving.

Free feasibility study: zoning, buildable size, and matching floor plans in one call. No obligation.