Los Angeles County ADU Permit & Building Guide
Building an ADU in Los Angeles County is a practical way to add living space, generate rental income, and increase the value of your property. The County has clear regulations that allow homeowners to construct additional dwelling units while maintaining neighborhood character. At Apex Homes, we specialize in building ADUs in Los Angeles County, handling everything from design and permitting to construction so homeowners can bring their vision to life without unnecessary delays.
ADU Regulations in Los Angeles County
For single-family lots, homeowners may build one detached or attached ADU and one Junior ADU (JADU). In multi-family zones, up to eight detached ADUs can be added, or attached ADUs may occupy up to 25% of existing units. Detached ADUs may be up to 1,200 square feet, while attached ADUs can be up to 50% of the existing dwelling’s size (though new buildings may not allow an attached ADU). JADUs are limited to 500 square feet.
Setbacks for side and rear property lines are a minimum of four feet. Unit separation depends on ADU size: units 800 square feet or smaller must maintain at least six feet from the main dwelling and any accessory structures, while units larger than 800 square feet require at least ten feet of separation or must be attached to the main dwelling or garage.
Height limits vary depending on location: one-story ADUs can reach up to 16 feet, or 18 feet if located within half a mile of public transit. Two-story ADUs are permitted up to the zoning height limit, excluding basements, and must comply with all applicable zoning regulations. Unit separation between structures generally ranges from six to 25 feet, depending on ADU size and layout.
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The Los Angeles County ADU Permitting Process
To build an ADU in Los Angeles County, homeowners should first verify zoning compliance and prepare a complete set of plans, including site plans, floor plans, elevations, structural details, and Title 24 energy compliance documentation. Applications are submitted to the Los Angeles County Department of Public Works or Building and Safety Division, where review times typically range from two to four months depending on the scope of the project. Once approved, permits are issued, and construction can begin. Apex Homes provides full-service support, managing the entire process from design and permitting to final construction.
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.