Los Angeles faces one of the most severe housing shortages in the country, with median home prices soaring and rental vacancies at historic lows.
In response, Additional Dwelling Units (ADUs) have emerged as a powerful solution offering affordable, flexible housing options built right into existing residential lots. Thanks to recent changes in California law, building an ADU is now faster, easier, and more accessible than ever for LA homeowners.
An Additional Dwelling Unit, or ADU, is a self-contained living space with its own kitchen and bathroom. It can be a backyard cottage, a garage conversion, or an addition to your home. There’s also a smaller version called a Junior ADU (JADU), which is built within the main house and is limited to 500 square feet. These units are becoming increasingly popular in Los Angeles not just for rental income, but also for housing family members or creating more usable space on your property.
In this article, we’ll explore the best additional dwelling unit plans for Los Angeles homes, especially in light of the 2025 legal updates that make ADU construction even more attractive. Here’s what you’ll learn:
What ADUs and JADUs are, and how they differ under LA regulations
How the 2025 California ADU laws simplify zoning, permitting, and design options
The best ADU designs for generating rental income versus housing family members
Step-by-step guidance on permitting, pre-approved plans, and approval timelines
Key benefits of building an ADU, including financial, personal, and community advantages
By the end of this post, you’ll have a clear understanding of which ADU plan best fits your goals, whether you’re looking to add a rental unit, create space for aging parents, or invest in your property’s long-term value and how to get started legally and efficiently in Los Angeles.
Understanding ADU Types in Los Angeles
As homeowners in Los Angeles consider additional dwelling unit plans for their properties, it’s crucial to understand the two primary types of units allowed: Accessory Dwelling Units (ADUs) and Junior Accessory Dwelling Units (JADUs). Each type serves different needs and comes with its own design, legal, and functional considerations.
What is an ADU?
An Accessory Dwelling Unit (ADU) is a self-contained residential structure located on the same lot as a primary home. It includes a full kitchen, bathroom, living area, and separate entrance. ADUs can be up to 1,200 square feet in size and come in various configurations, such as:
Detached ADUs: Freestanding backyard cottages or small houses that offer the most privacy and flexibility.
Attached ADUs: Built as extensions to the main house, sharing one wall while still having a separate entrance.
Garage Conversions: Existing garages converted into livable units, often the most cost-effective option.
ADUs are popular for long-term rentals, multigenerational housing, or even as home offices or guest suites. Thanks to recent zoning changes, many single-family and multifamily properties in Los Angeles are now eligible to add an ADU.
What is a JADU?
A Junior Accessory Dwelling Unit (JADU) is a smaller type of unit carved out from the existing square footage of a single-family home. These units are limited to 500 square feet and must be located within the main residence, such as in a converted bedroom or part of a garage.
JADUs typically:
Share a bathroom with the main house
Have a separate entrance and a small kitchen or kitchenette
Require owner occupancy in either the JADU or the main home
JADUs are ideal for housing aging parents or adult children while maintaining some level of independence and privacy. They are also easier and less expensive to build, making them a great entry point for homeowners new to ADU development.
Legal and Regulatory Framework for ADUs in Los Angeles
Key Zoning and Code Requirements
Los Angeles has adopted flexible ADU zoning standards to encourage development, but several key requirements still apply:
Lot Coverage and Floor Area Ratio (FAR): These determine how much of your lot can be developed.
Height Limits: ADUs are generally limited to 16 feet, though some zones allow taller structures.
Parking Requirements: No parking required within 0.5 miles of public transit. True for most of LA.
Setbacks: Detached ADUs typically need at least 4-foot side and rear setbacks.
2025 Legislative Updates
Two critical legal changes are reshaping the ADU landscape in 2025:
Assembly Bill 2533: Streamlines the permitting process, removes certain impact fees, and allows for the legalization of previously unpermitted ADUs.
ZA Memo 143: Aligns Los Angeles zoning codes with state law, allowing homeowners to build both an ADU and a JADU on the same lot. It also clarifies owner-occupancy and deed restriction requirements.
These updates make it easier than ever for LA homeowners to add legal, code-compliant ADUs to their properties.
Best ADU Plans for Rental Income
Detached and Garage Conversion Plans
Detached ADUs and garage conversions are among the most effective structures for rental purposes:
Detached Units: Offer total privacy and can be designed as one-bedroom or studio apartments.
Garage Conversions: Reuse existing structures to cut costs and provide affordable rental housing.
Popular rental-ready features include:
Full kitchens with modern appliances
In-unit washer/dryer
Private outdoor patios or small yards
Soundproofing for tenant comfort
Legal and Financial Incentives for Rentals
Renting out an ADU can create steady passive income, but owners must follow a few rules:
Deed Restrictions: Especially for JADUs, to prevent separate sale from the main home.
Owner-Occupancy: Required for JADUs; you must live in the home or JADU.
Tax and Permit Incentives: Reduced impact fees and possible property tax benefits.
Rental ADUs are a smart long-term investment, especially in a high-demand market like Los Angeles.
Best ADU Plans for In-Law Units and Family Use
Attached and Internal ADU Designs
For elderly parents or adult children, attached or internal ADUs offer easy access and family connection while maintaining privacy:
Single-Level Layouts: Safer for seniors avoiding stairs.
ADA-Compliant Features: Include ramps, wide doorways, walk-in showers.
Shared Outdoor Spaces: Encourage interaction without intrusion.
These designs allow families to stay close while giving everyone their own space.
JADUs for Multigenerational Living
JADUs are especially useful for multigenerational households:
Low-Cost Construction: Use existing square footage.
Shared Utilities: Reduce setup and monthly utility bills.
Proximity and Independence: Ideal for elderly parents who need some autonomy.
For families balancing care needs and independence, JADUs offer a practical solution.
Permitting, Pre-Approved Plans, and Approval Timeline
Using Pre-Approved Plans
The YOU-ADU program from the Los Angeles Department of Building and Safety (LADBS) includes:
Architect-designed plans already reviewed for code compliance
Lower design costs and faster approvals
Designs for lots of varying shapes and sizes
Using a pre-approved plan can save months and thousands of dollars.
Permit Process and Timeline
Here’s what the process looks like:
Plan Submission: Submit site and architectural plans
Zoning Review: Ensure compliance with zoning and setbacks
Plan Check: LADBS checks structural and code compliance
Permits & Construction: Start building and schedule inspections
With pre-approved plans, the process can take just 30-60 days.
Design and Cost Considerations
Budgeting for ADU Construction
Here’s a general cost range:
Garage Conversions: $100,000 – $120,000
Detached New Builds: $180,000 – $400,000
JADUs: Often under $100,000
Prefab ADUs are also growing in popularity for budget-conscious homeowners.
Choosing the Right Layout
Consider:
One-Story vs. Two-Story: Accessibility vs. maximizing space
Attached vs. Detached: Cost vs. privacy
Use Case: Rentals need full amenities, in-law units may prioritize comfort
Tailor your layout to your long-term goals and property constraints.
Benefits of Building an ADU in Los Angeles
Income, Flexibility, and Housing Solutions
Rental Income: Offset your mortgage or fund retirement
Family Housing: Keep loved ones close while preserving independence
Community Impact: Help address LA’s housing crisis sustainably
ADUs are a win-win for homeowners and neighborhoods alike.
Programs and Support Services
LA ADU Accelerator Program: Matches low-income seniors with homeowners offering ADUs in exchange for steady rent
Professional ADU Firms: Provide turnkey services from design to construction
Choosing the Right ADU Plan for Your Los Angeles Home
As Los Angeles continues to face a growing housing shortage, Additional Dwelling Units (ADUs) and Junior ADUs (JADUs) offer homeowners a smart, flexible solution. Whether you’re aiming to generate rental income or provide comfortable living space for family members, understanding the differences between detached, attached, and internal units, as well as the legal framework under California’s 2025 laws is essential. From garage conversions to ADA-compliant in-law suites, there are ADU plans tailored to every need and budget.
With pre-approved plans, streamlined permitting, and financial incentives now available, building an ADU has never been more accessible. These units not only add value to your property but also contribute to solving LA’s housing crisis in a practical, community-friendly way.
If you’re ready to take the next step, explore your options with a trusted local expert and city guidance.
References
LADBS YOU-ADU Standard Plan Program: https://www.ladbs.org/adu/standard-plan-program/approved-standard-plans
ZA Memo 143 – City of Los Angeles Ordinance: https://cityclerk.lacity.org/onlinedocs/2016/16-1468_ORD_186481_12-19-2019.pdf
California State ADU Laws Overview (AB 2533 and others): https://en.wikipedia.org/wiki/Secondary_suite
