Trusted ADU Contractor in California Washington

Trusted by 3,500+ Homeowners for Complete ADU Design, Permitting & Build Services.

Proud Moment

Design-Build Excellence

Urbatect Enters Business Hall of Fame

Four Years in a Row

2025 Award 2024 Award 2023 Award 2022 Award

Let’s Build Your ADU—Your Way!

Ready to turn that ADU  dream into reality? Whether you’re looking to design a custom  ADU or want to fast-track things with a ready-to-build plan, we’ve got options that fit your style, timeline, and budget.

Custom ADUs

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Custom ADUs

Tailored to your site, budget, and style — with finishes you choose for a space that’s truly yours.
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Build-Ready ADUs

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Build-Ready ADUs

Choose from our library of designer-curated floor plans. Save time and money without sacrificing quality.
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Our Completed Projects

Addition to a Senior Living Facility

Lynnwood

Amburose Custom Home

Fremont

Camden ADU

Oakland

Cameron ADU

San Leandro

Custom Home​

Santa Rosa​

Flying Lady Winery

St. Helena

Gallegos ADU

Watsonville

Governor ADU

Harbor City

Millbrook Residence

Santa Rosa

Modern ADU

Whittier

Modern Custom Home

Santa Rosa

Multi Family Development

Location: San Diego

Paxton custom home

Santa Rosa

Perlita ADU

Los Angeles

Salvator Apartments

Sacramento

Sawgrass Residence

Santa Rosa​

Shaff ADU

Aptos

Sierra Home

Sacramento

Smiley custom home

Olympic Valley

St. Leo’s Apartments

Redwood

Studio Loft

San Diego

Tynan Village Apartments

Salinas

Yangzom ADU

Alameda

Custom ADUs: Perfect Fit for Your Home & Lifestyle

What’s an Accessory Dwelling Unit (ADU)?

Think of an ADU as your property’s hidden gem.

Also known as a granny flat, in-law suite, or backyard cottage, an ADU is a private, self-contained mini-home built right on your lot. It includes its own kitchen, bathroom, and entrance—perfect for hosting guests, housing family, or earning rental income.

And here’s the best part: California & Washington laws now make it easier than ever to build one. Whether you’re looking to add space, boost property value, or generate income, an ADU is a smart, flexible solution. Let’s make it happen!

Types Of ADUs

1. Attached ADUs

Attached ADUs are connected to the main home, usually as a side or rear addition, and may have a separate or shared entrance. Junior ADUs (JADUs) are smaller, up to 500 sq. ft., and built within the home’s existing space. They may share a kitchen or bathroom, offering a more affordable housing option.

2. Detached ADUs

Stand-alone structures located on the same lot as the primary home. These units are fully independent and offer complete privacy. Examples include one story or two story backyard cottages, studio units, casitas, or converted outbuildings. Detached ADUs are ideal for homeowners who want to maximize space without altering the existing home. They offer added privacy and are a great option for generating rental income.

3. Interior ADU

Created by converting a part of the existing home into a separate living space. These can include basements, attics or even an entire floor. Interior ADUs are a great way to utilize underused space within the home while maintaining the property’s original footprint.

4. Garage Conversion

Transform your attached or detached garage into a livable ADU. Under California law, in most cases, homeowners are allowed to convert garages without needing to replace the lost parking, making this a popular and cost effective option. You can also build a second-story ADU above the garage or construct a new structure that combines parking and living space.

ADU Benefits

More space

More space

Create additional living space without the hassle and expense of moving. ADUs can serve as a home office, guest house, artist’s studio, and more—tailored to your unique needs.

Higher property value

Higher property value

ADUs not only boost your home’s resale value—they also increase equity, giving you more financial flexibility even before you sell. The return on investment from designing and building an ADU is exceptionally high.

Passive rental income

Passive rental income

ADUs can be rented out to generate passive income, helping offset mortgage payments, property taxes, and other expenses.

Home for Loved Ones

Home for Loved Ones

An ADU offers a private, comfortable space for family—perfect for aging parents, adult children, or visiting relatives. Keep your loved ones close while giving them the independence they need, right in your backyard.

Our Step by Step Approach

1
Free Consultation
2
Site Visit
3
Designing Services
4
Permits & Approvals
5
Construction

1,000+ Happy Customers.
Real Stories, Real Results.

B
22:04 11 Apr 25
I used Urbatect for the structural review of my renovation plans. Mayank and his team were very prompt with their work for any follow up that was needed by the city as well. Overall a great team to work with. Highly recommended!
Ondene Pena
22:30 05 Dec 24
I had a wonderful experience talking with John Soliz, we then had a Zoom meeting with some of my family which proved to be professional and very informative.
I truly appreciated his time and expertise.
Response from the owner 17:21 25 Jan 25
Hi Ondene - Thank you for your kind words! We’re so glad to hear that John Soliz was able to provide a professional and informative experience during your Zoom meeting. We truly appreciate your feedback and look forward to assisting you further!Best regards,The Urbatect Team
louie nilsson
08:00 03 Dec 24
I’ve been talking with John Solis about building an ADU over my garage and he has been super helpful and communicative. He’s very knowledgeable and has shown us the process and options for our space. We look forward to working with Urbatect in the near future. Thanks John!
Response from the owner 17:23 25 Jan 25
Hi Louie - Thank you for taking the time to share your feedback! We’re so glad John Soliz has been able to guide you through the process of planning your ADU with clarity and expertise. It’s exciting to hear about your project, and we’re looking forward to collaborating with you soon to make it a reality.Best regards,The Urbatect Team
Marco Onton
23:58 27 Nov 24
Urbatec professional services was a great experience for me. From the beginning It was very nice coordination about the Project needs I had and they were very attentive to details. They finished the Project in a timely manner, the whole Project process went smooth. Special mention to Erick and Mayank, they were great about coordination and communication needed to complete the Project.
Response from the owner 01:59 28 Nov 24
Thank you so much for sharing your experience! We’re thrilled to hear that the project went smoothly and that the coordination and attention to detail met your expectations. Erick and Mayank are truly dedicated to keeping things on track, and we’ll be sure to share your kind words with them.It was a pleasure working with you. If you ever have another project in mind, don’t hesitate to reach out—we’d love to work with you again!
Alejandro Sanchez
17:33 30 May 24
Great group of guys to work with. Always following up and very patient with roadblocks along the way.
As I figured out how to design my first house and needed engineering plans for my drawings, they guided me through the process so I will be able to submit to the city for building permits. Will have more plans coming their way!
Response from the owner 05:47 09 Jul 24
Hi Alejandro- Thank you for your wonderful review! We’re thrilled to guide you through the design and permitting process for your first house. It means a lot to us to know that our patience and follow-ups made a difference. We're excited to continue working with you on future projects!Thank you!
Milan Jackson
23:08 18 May 24
We contacted Urbatect Development to plan an ADU for our property in Richmond CA. John was extremely helpful and patient and anwsered all of our questions thoroughly. I really appreciate his transparency snd honesty.
Response from the owner 05:51 09 Jul 24
Hi Milan - Thank you for your thoughtful feedback! We're really glad to hear that John made the planning process for your ADU in Richmond, CA, smooth and informative. We're excited to continue working with you and making your project a success!Thank you!
Amanda F
22:31 26 Apr 24
I had a consultation with Alex Zambrano regarding building an ADU. He was very knowledgeable and understanding. He frequently stopped and asked me what questions do I have during our meeting. Did not use confusing lingo to confuse me at all during our meeting either. He did not make me feel bad at all even though my intentions were purely information on potential future ADU on a future purchase of a home with a bigger lot. If everyone at Urbatect is as friendly and patient as Alex is, the. All your clients are in great hands!!!!
Response from the owner 05:54 09 Jul 24
Hi Amanda- Thank you for your feedback on Alex! We're thrilled he could assist with your ADU consultation and was straightforward and helpful. We aim to keep things clear and friendly for all our clients. Whenever you're ready to move forward, we're here to help!Best regards,The Urbatect Team

The Urbatect Advantage

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FAQs

The full process of designing, permitting, and constructing a new accessory dwelling unit (ADU) typically takes 10 to 16 months, depending on the complexity of your project, city processing times, and coordination with you throughout each phase. Here’s a general breakdown:

Design & Permitting: 2 to 4 months
This typically includes concept plans, schematic and design development, and Title 24 compliance. Multiple design meetings and revisions are typically included during this phase to ensure your vision is fully incorporated in the design.

Permitting: 3 to 4 months
Once plans are submitted, the city reviews them in plan check cycles. Timelines vary by jurisdiction and can depend on the city’s backlog as well, and may include revisions to the plans based on city feedback before final permit issuance.

Construction: 5 to 8 months
Construction duration typically depends on unit size, complexity, site conditions, and city inspection timelines. This includes everything from site prep and framing to MEP installation, finishes, and the final Certificate of Occupancy.

We aim to complete ADU projects in 10 to 12 months whenever feasible, but always advise planning for up to 16 months to account for external delays.

In California, the maximum size of your ADU depends on whether it’s attached or detached, your lot size, and your local city or county’s zoning regulations.

  • Detached ADUs are allowed up to 1,200 sq. ft. in many areas, but state law requires all jurisdictions to permit at least 800 sq. ft., regardless of lot coverage, setbacks, or floor area ratio limits.
  • Attached ADUs can typically be up to 50% of the size of your primary home, but must be allowed at least 800 sq. ft., even if 50% would be less.

Local ordinances may allow more—but cannot restrict you below these state minimums. Every property is unique and may have specific conditions—such as lot configuration, easements, setbacks, or local overlays—that impact the maximum ADU size.

We offer a free property-specific assessment as part of our initial process—even before a contract is signed—to help define your scope and guide you clearly. Contact us at (559) 412-8841 or info@urbatect.com, and we’ll assess your site to confirm the maximum ADU size allowed under your city’s rules.

Adding an ADU is not just a smart way to maximize your property—it’s a long-term investment that boosts value, generates income, and offers greater flexibility for your evolving needs. Here’s why building an ADU makes strong financial sense:

  • Boosts overall property value
  • Builds equity immediately by adding livable square footage and a permitted unit to your asset
  • Strong return on investment (ROI) in both resale and rental markets
  • Generates passive rental income - short- or long-term
  • Offers flexibility for future use (guest house, home office, aging parents, etc.)
  • Provides private space for family or visitors
  • More cost-effective than buying a new property or undertaking major home additions
  • Adds diversification to your real estate investment portfolio
  • Supports sustainable living with compact, energy-efficient design options

No—owner-occupancy requirements have been eliminated for ADUs across California, with the exception of Junior ADUs (JADUs). This means you’re not required to live on the property to rent out your ADU. However, JADUs still require the property owner to reside on-site, either in the main home or the JADU.

Not necessarily. While pre-approved plans can be faster to permit, they still need to meet your specific site conditions and local city regulations, which can result in costly changes or delays if they don’t align perfectly. At Urbatect, we specialize in custom solutions that are designed to minimize revisions, avoid surprises, and ensure smoother permitting—helping you save time and money in the long run.