Can an ADU Be a Primary Residence?

In California’s tight housing market, more and more people are asking a smart, practical question: can an ADU be a primary residence? The short answer is yes—and it’s a game-changer. Living in an ADU (accessory dwelling unit) is no longer limited to aging parents or college kids. Thanks to California’s evolving ADU laws, it's fully legal—and in many cases, ideal—for homeowners to live in their own backyard units.

With the right setup, you can legally live in your ADU full-time—whether you're renting out the main home, downsizing for financial flexibility, or embracing a minimalist, self-contained lifestyle. These units offer privacy, lower utility costs, and full legal recognition under updated state and city ordinances.

As a leading general contractor in Los Angeles, NEO Builders has been designing and building ADUs since 2017. Our team specializes in turning garages and backyard spaces into beautiful, livable homes—ready for full-time use. Book your free ADU consultation today to see if your lot qualifies.

Can an ADU Be a Primary Residence in California?

Yes, under California law, an ADU can absolutely be used as a primary residence. That means you can legally live full-time in an ADU on your own property—as long as it meets permitting, zoning, and livability standards. This shift is part of a broader effort to expand housing options across the state without requiring large-scale development.

Moving into your ADU while renting out your main house is one of the most effective strategies for building long-term wealth—because it turns your primary home into an income-producing asset without having to leave your property. It’s also a great option for homeowners nearing retirement or anyone looking to reduce overhead and simplify their living situation.

Detached vs. Attached ADUs as Primary Homes

Detached ADUs, such as backyard cottages or new construction units, offer the most privacy and feel the most like a standalone home. They’re perfect for homeowners who want complete separation from the main residence. Attached ADUs, on the other hand, share at least one wall with the main home—often converted garages or room extensions—but still provide a fully independent living setup.

Both are 100% legal to use as a primary home in California, provided they're built to code. 

Check out our ADU property tours to see the difference firsthand.

Why More Homeowners Are Choosing to Live in Their ADUs

Downsizing into an ADU gives you more flexibility. You can stay on your property while drastically lowering your living expenses. Many homeowners are choosing to live in their ADUs full-time to generate rental income from the main house, reduce utility bills, or support multi-generational living.

Primary residence ADU benefits include lower upkeep, less clutter, and the option to remain in high-value neighborhoods without selling. For many, it’s a lifestyle upgrade—not a downgrade.

ADU Requirements for Primary Residence Use

To legally live in your ADU full-time, it needs to meet specific standards for safety, function, and comfort. These aren’t overly complex—but they’re critical to get right if you want to avoid future issues.

Zoning and Permitting Essentials

Every city has slightly different rules, but in general, you’ll need to follow your municipality’s guidelines for setbacks, height restrictions, and lot coverage. 

For example, Los Angeles requires a minimum four-foot setback from the rear and side property lines for detached ADUs. Height limits vary, but most cities cap ADUs at 16 to 25 feet. Lot coverage rules may limit how much of your property can be built on—especially for smaller or irregularly shaped lots, but you are almost always guaranteed an 800 sq ft ADU

You’ll also need to pull a valid permit through your local building department and pass inspections for things like structural safety, energy compliance, and fire separation. Finally, ADU occupancy regulations vary by city; some cities may limit short-term rentals or require you to designate which unit is the primary residence. Owner occupancy is not required if you decide to rent out both the ADU and primary home..

Minimum Size, Layout, and Amenities

Your ADU must include all essentials for full-time living: a kitchen (with a cooktop and fridge), a bathroom, a place to sleep, and independent access. Most ADUs in California range from 400 to 1,200 square feet. While there’s no strict minimum size, the layout must meet basic space and building code standards.

NEO Builders offers flexible floor plans with smart design features—ensuring every square foot is optimized for real-life use.

Utility Standards and Independent Systems

Your ADU must have water, sewer, and electricity, and in some areas, a separate utility meter may be required. This varies by jurisdiction, but independent systems are usually recommended—especially if you plan to rent out either unit later on.

Heating, cooling, and ventilation also need to meet energy efficiency codes (Title 24 in California). NEO Builders is the fastest ADU builder in Los Angeles and ensures all utility work is done to code, the first time.

California Laws That Make Living in an ADU Legal

AB 1033 and Condo-Style ADU Sales

Passed in 2023, AB 1033 gives cities the option to allow ADUs to be sold separately from the main home as condominiums. That means your ADU could legally function like a townhouse or condo—ideal if you want to transfer ownership or build equity independently from your main residence.

It’s also a game-changer for homeowners wondering, can I live in my ADU and treat it as a long-term investment? In cities that opt in to AB 1033, the answer is yes. At this time, the only city that has passed a condo-ization ordinance is San Jose, but other cities are considering similar measures. 

SB 9, SB 13, and AB 68 Explained Simply

SB 9 allows homeowners to split their single-family lots into two parcels, making it easier to build additional housing, including ADUs, on each new lot. This can expand options for homeowners who want more flexibility in how they use or develop their property.

SB 13 and AB 68 removed several of the biggest hurdles for building ADUs across California. These bills eliminated things like owner-occupancy requirements, which previously forced owners to live on-site, and minimum lot size restrictions, which often disqualified smaller properties. 

Together, they’ve helped simplify ADU primary residence rules in CA, giving homeowners more freedom to live in their units or rent them out long-term without complicated legal barriers.

Local Variations in Los Angeles and Nearby Cities

Los Angeles has some of the most ADU-friendly rules in Southern California. For example, you don’t need to add new parking spaces if your property is within a half-mile of public transit, and HOAs can’t legally ban ADUs—though they may apply design restrictions. In contrast, cities like Santa Monica or Glendale often have stricter review processes and longer timelines.

Because ADU housing laws in Los Angeles can change frequently, NEO Builders stays up to date to keep your project compliant and on track. Book a free ADU consultation to see how straightforward the process can be.

Can an Attached Garage Conversion ADU Be a Primary Residence?

How Garage ADUs Are Permitted for Full-Time Living

If permitted and built to code, a garage conversion can be used as your full-time home. That means insulation, egress windows, ceiling height, and permanent foundations must all meet code. Garage conversions are a smart, cost-effective way to maximize your lot without starting from scratch.

Advantages of Living in a Converted Garage ADU

The biggest perk? Affordability. Converting existing space is far cheaper than new construction, assuming the space is structurally sound. Plus, garage ADUs offer quicker timelines and less disruption to your property. They’re a great fit for singles, couples, or anyone looking to simplify while staying rooted in a familiar neighborhood.

At NEO Builders, we specialize in garage conversions—handling everything from structural assessments and permits to custom layouts and energy-efficient upgrades that make the space truly livable.

What Homeowners Should Consider Before Moving In

Think about noise insulation, ceiling height, natural light, and the flow of your floor plan. If you're planning to age in place or rent out the main home, privacy will be key.

Is Living in an ADU the Right Move for You?

Financial Benefits: Lower Bills and Rental Income

Living in an ADU can significantly lower your living expenses—utilities, taxes, and maintenance—while also generating rental income from your main home. It’s a powerful wealth-building strategy, especially in markets where home prices are already high.

Lifestyle Benefits: Minimalism, Privacy, and Proximity

Living small doesn’t mean living less. For many, ADUs offer just the right amount of space and total independence. You’re close to family, friends, and your own backyard—just without the overhead of a large home.

Potential Drawbacks: Size, Layout, and Resale Implications

Of course, an ADU comes with trade-offs. Limited square footage means creative storage and furniture planning. You may also need to clarify the setup when it’s time to sell—some buyers may not understand the value of the arrangement, while others will see it as a goldmine.

Steps to Legally Establish an ADU as Your Primary Residence

Check Zoning, Apply for Permits, Ensure Code Compliance

Before moving in, verify your ADU is legal for full-time occupancy. This includes passing inspections and obtaining your Certificate of Occupancy. NEO Builders handles this step for every project to avoid delays and surprises.

Work With Experienced ADU Builders

DIY isn’t the move here. You need a team that understands both design and code. NEO Builders has completed hundreds of projects in LA and specializes in ADUs built for full-time living—not just rentals.

Add Independent Addresses and Utility Meters If Needed

In many areas, you can assign your ADU its own address and separate utilities, which is especially useful if you plan to rent or sell. These upgrades also make primary residence use more seamless and compliant.

FAQs: Can an ADU Be a Primary Residence?

Can you live in an ADU full-time in Los Angeles?

Yes, as long as the ADU is permitted and meets all livability standards.

Do ADUs need separate utilities to be a primary residence?

Not always, but separate systems are recommended for flexibility and resale.

Can you rent out the main house and live in the ADU?

Absolutely—and it’s a smart financial move for many homeowners.

Are you allowed to sell an ADU separately in California?

In cities that opt into AB 1033, yes—though not all municipalities have adopted it yet. At this time, only San Jose has adopted this.

How do taxes and insurance work if the ADU is your primary home?

Your property may be reassessed depending on the value and modifications. Talk to a local insurance and tax advisor to optimize your setup.

Ready to Build a Legal, Livable ADU in Los Angeles? Book Your Free Consultation

Living in your ADU is totally legal—and can be incredibly smart. NEO Builders can help you make it happen, from permits to keys in hand. Book a free ADU consultation and let’s explore how to turn your lot into a lifestyle upgrade.

We handle everything in-house and lead with empathy, driven by a genuine commitment to help homeowners navigate California’s housing crisis. When you work with us, you’re partnering with a team that values trust, transparency, and results.