How much does it cost to build an ADU in Los Angeles?

A garage conversion typically runs $150,000 to $250,000 depending on the condition of the existing structure and finish level. A detached new-construction ADU generally ranges from $250,000 to $400,000+. We provide detailed estimates based on your specific property and goals.

How long does it take to build an ADU?

From initial consultation to move-in, plan on 9 to 14 months for most ADU projects — including the permitting phase. Garage conversions are often faster since the structural shell already exists. Permitting alone can take 3 to 6 months in LA depending on the project.

Do I need permits to build an ADU?

Yes. An unpermitted ADU cannot be legally rented and can create serious problems when you sell or refinance. All ADU construction through ARM is fully permitted.

Can I rent my ADU on Airbnb?

Short-term rental regulations in Los Angeles are complicated and subject to change. Generally, you can only rent your primary residence short-term, which affects how an ADU can be used. We recommend checking current city regulations or speaking with a real estate attorney before planning for short-term rental income.

What's the difference between an ADU and a JADU?

An ADU is a fully self-contained unit — it can be detached or attached to the primary home, and has its own entrance, kitchen, and bathroom. A JADU (Junior ADU) is smaller (up to 500 sq. ft.), carved out of existing space within the home, and requires the owner to live on the property. JADUs are lower cost but more limited.

Can I build an ADU if I have a multi-family property?

Yes. Since 2020, California law allows multi-family property owners to convert existing non-livable spaces — garages, storage rooms, laundry rooms — into permitted ADUs. The number of units you can add depends on your existing unit count and lot conditions. Get in touch and we’ll assess your specific property.

Will an ADU increase my property taxes?

In California, adding an ADU triggers a reassessment only on the value of the new construction — not your entire property. Your existing assessed value stays the same. The new ADU value is added to your tax base.

ADU Builder

ADUs & Garage Conversions in Los Angeles

Add a livable unit to your property — for rental income, family, or guests. We've built over 30 ADUs across LA and handle everything from permits to keys.

Free Construction Consultation

Let's talk about your project.

No pressure. No obligation. We respond within one business day.

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Your property can do more than it's doing right now. An ADU — accessory dwelling unit — is a self-contained living space built on your existing lot, and it's one of the smartest investments a Los Angeles homeowner can make. Rental income, multigenerational living, a home office, space for aging parents — the use cases are as different as the people building them. ARM Builders has been building ADUs in Los Angeles since the state laws changed to make them easier to permit and build. We've completed over 30 units — detached ADUs, garage conversions, attached units, and junior ADUs — and we handle the entire process from design through final inspection.

Talk to Us About Your ADU

what we build

Types of ADUs We Build

Detached ADU

A fully separate structure built in your backyard or elsewhere on your lot. The most flexible option — up to 1,200 sq. ft., its own entrance, its own address.

Garage Conversion

Convert an existing attached or detached garage into a permitted, livable ADU. One of the most cost-effective ways to add a unit because the structure is already there.

Attached ADU

An addition built onto your existing home with its own entrance and living space — sharing a wall with the primary residence but fully self-contained.

Junior ADU (JADU)

Up to 500 sq. ft. carved out of existing space within the primary residence. A lower-cost entry point if you want to generate income without a full build. Owner-occupancy is required.

Multi-Family ADU

Since 2020, multi-family property owners can convert existing non-conforming spaces — garages, recreation rooms, laundry rooms — into permitted units. If you own an apartment building, this is worth exploring.

Find Out Which Type Is Right for You

financial case

Why an ADU Makes Financial Sense in Los Angeles

Los Angeles has one of the highest rental markets in the country. An ADU on your property generates income from day one of tenancy — and unlike purchasing an investment property, you're building equity on land you already own.

At those rates, most ADU construction costs are recovered within 4 to 5 years on a long-term rental — faster on short-term platforms like Airbnb. After that, it's income.

The LA ADU Accelerator Program The City of Los Angeles runs a program that connects ADU owners with pre-screened tenants and provides guaranteed rent payments for qualifying units. It's a meaningful option for homeowners who want stable income without the hassle of finding and managing tenants independently. More information at adu.lacity.org.

Let's Build Something

Rental income potential (LA ADU Accelerator Program rates):

$1,869/month

Studio ADU

$2,165/month

1-bedroom ADU

$2,663/month

2-bedroom ADU

$3,135/month

3-bedroom ADU

Rates reflect the LA ADU Accelerator Program and are subject to change.
Verify current rates at adu.lacity.org.

HOW IT WORKS

How We Build Your ADU

Start the Process

Free Consultation

We assess your property, discuss your goals, and tell you which ADU type makes the most sense for your lot, your budget, and your timeline.

Design & Plans

We coordinate architectural plans tailored to your property and LA’s ADU ordinance requirements — including setbacks, height limits, and utility connections.

Permits & Approvals

We handle all city submissions and approvals. LA’s ADU permitting has gotten faster in recent years, but it still requires experience to navigate correctly. We’ve done it over 30 times.

Construction

Our team builds the unit. Weekly updates, photos, and direct access to Aaron throughout. We use vetted subcontractors and suppliers we’ve worked with for years.

Final Inspection & Handover

We manage the final city inspection and walk the completed unit with you before handing over the keys.

WHY ARM FOR YOUR ADU

Why Homeowners Choose ARM for Their ADU

Over 30 completed ADUs in Los Angeles. We know what the city requires, where the process stalls, and how to keep your project moving.
Full permit management. ADUs without proper permits can't be legally rented. We handle every submission correctly from the start.
Civil engineer oversight. Aaron Weiss reviews every ADU for structural integrity and code compliance — especially important for garage conversions where the existing structure is being repurposed.
One point of contact. Aaron's mobile number, from first conversation to final inspection.
Licensed and insured. CSLB Lic. #915352, Class B. Your investment is protected.

Let's Build Something

ADUs in Los Angeles Frequently Asked Questions

How much does it cost to build an ADU in Los Angeles?
A garage conversion typically runs $150,000 to $250,000 depending on the condition of the existing structure and finish level. A detached new-construction ADU generally ranges from $250,000 to $400,000+. We provide detailed estimates based on your specific property and goals.
How long does it take to build an ADU?
From initial consultation to move-in, plan on 9 to 14 months for most ADU projects — including the permitting phase. Garage conversions are often faster since the structural shell already exists. Permitting alone can take 3 to 6 months in LA depending on the project.
Do I need permits to build an ADU?
Yes. An unpermitted ADU cannot be legally rented and can create serious problems when you sell or refinance. All ADU construction through ARM is fully permitted.
Can I rent my ADU on Airbnb?
Short-term rental regulations in Los Angeles are complicated and subject to change. Generally, you can only rent your primary residence short-term, which affects how an ADU can be used. We recommend checking current city regulations or speaking with a real estate attorney before planning for short-term rental income.
What's the difference between an ADU and a JADU?
An ADU is a fully self-contained unit — it can be detached or attached to the primary home, and has its own entrance, kitchen, and bathroom. A JADU (Junior ADU) is smaller (up to 500 sq. ft.), carved out of existing space within the home, and requires the owner to live on the property. JADUs are lower cost but more limited.
Can I build an ADU if I have a multi-family property?
Yes. Since 2020, California law allows multi-family property owners to convert existing non-livable spaces — garages, storage rooms, laundry rooms — into permitted ADUs. The number of units you can add depends on your existing unit count and lot conditions. Get in touch and we’ll assess your specific property.
Will an ADU increase my property taxes?
In California, adding an ADU triggers a reassessment only on the value of the new construction — not your entire property. Your existing assessed value stays the same. The new ADU value is added to your tax base.

Request Your Free Consultation

Ready to Build Your ADU?

Whether you're looking for rental income, space for family, or a way to maximize what your property can do — an ADU is one of the most valuable projects a Los Angeles homeowner can take on. Let's talk about yours.

Request Your Free Consultation

ARM Builders, Inc. · CSLB Lic. #915352 · 877.755.1350 · armbuildersinc.com