Accessory Dwelling Units, commonly known as ADUs, have become one of the most popular home improvement projects in Los Angeles. Thanks to progressive California legislation and growing demand for housing, building an ADU on your property is now easier and more financially rewarding than ever before. Here is everything you need to know to get started in 2026.
What Exactly Is an ADU?
An ADU is a secondary residential unit built on a single-family lot. These self-contained living spaces include their own kitchen, bathroom, and sleeping area. In Los Angeles, ADUs come in several forms:
- Detached ADU – A standalone structure built in your backyard, separate from the main house
- Attached ADU – An addition built onto the existing home with its own private entrance
- Garage Conversion – Transforming an existing garage into a livable dwelling unit
- Junior ADU (JADU) – A smaller unit of up to 500 square feet created within the existing footprint of the main home
California ADU Laws – What Changed and Why It Matters
California has been steadily removing barriers to ADU construction since 2017. Key provisions that benefit Los Angeles homeowners include the elimination of owner-occupancy requirements for most ADUs, reduced setback requirements to just four feet from side and rear property lines, and the prohibition of local parking mandates for ADUs located within half a mile of public transit.
In addition, California law now allows homeowners to build both a standard ADU and a Junior ADU on the same single-family lot, effectively tripling the housing capacity of one property. Local jurisdictions cannot impose minimum lot-size requirements, and most impact fees have been waived for ADUs under 750 square feet.
The Los Angeles Permit Process – Step by Step
Navigating the City of Los Angeles permitting process is one of the most common concerns for homeowners. Here is a simplified overview of the steps involved:
- Feasibility assessment – Evaluate your lot size, zoning, setbacks, and utility access
- Design and planning – Work with an architect or design-build firm to create construction drawings
- Plan submission – Submit plans to the LA Department of Building and Safety (LADBS)
- Plan check and corrections – The city reviews plans and may request revisions
- Permit issuance – Once plans are approved, your building permit is issued
- Construction and inspections – Build the ADU with required city inspections at each phase
- Final sign-off – Obtain a certificate of occupancy from LADBS
The permit process in Los Angeles typically takes 8 to 16 weeks for plan approval, though timelines can vary depending on project complexity and city workload.
How Much Does an ADU Cost in Los Angeles?
Construction costs for ADUs in the greater Los Angeles area generally range from $150,000 to $350,000 or more, depending on size, finishes, and site conditions. A basic garage conversion on the lower end might cost $100,000 to $150,000, while a fully custom detached ADU with premium finishes can exceed $400,000. Key cost factors include foundation work, utility connections, roofing, and interior finishes.
Financing Options
Homeowners can fund ADU construction through several channels, including home equity lines of credit (HELOCs), cash-out refinancing, construction loans, and in some cases, CalHFA ADU grant programs. Many homeowners find that rental income from the completed ADU helps offset mortgage payments significantly.
Rental Income Potential
One of the biggest motivations for building an ADU in Los Angeles is the rental income opportunity. Depending on the neighborhood, size, and finishes, a one-bedroom ADU in LA can generate $1,800 to $3,200 per month in long-term rental income. In desirable areas like the Westside, Silver Lake, or the San Fernando Valley, rates can be even higher. This income stream can help homeowners pay down their mortgage, fund retirement, or simply cover the cost of the ADU construction over time.
Design Considerations
A well-designed ADU feels like a real home, not an afterthought. Important design elements include maximizing natural light with large windows and skylights, choosing space-efficient layouts with open floor plans, incorporating energy-efficient systems for HVAC and water heating, and selecting durable, low-maintenance exterior materials that complement the main house.
Thinking about adding an ADU to your Los Angeles property? ACE Design and Build has helped dozens of LA homeowners design and build beautiful, code-compliant ADUs from concept to completion. We handle permits, design, engineering, and construction under one roof so you do not have to juggle multiple contractors. Reach out to our team for a free property evaluation and find out what is possible on your lot.