ADU Contractors In Bay Area and LA
Ready to build your ADU?
Thinking about adding an ADU but not sure where to begin? W and W Builders Group is your trusted partner for turning ideas into reality. From initial design and permits to construction and finishing touches, we handle the entire process so you don’t have to stress. Our dedicated project managers, engineers, designers, and builders work together seamlessly to deliver the perfect space—whether you’re planning a rental unit, a private guest house, or a family gathering retreat. With our expertise, your ADU project in San Jose becomes smooth, stress-free, and built to last.
There are three primary types of ADUs:
Detached ADU
Built as a separate structure, often in the backyard, detached ADUs function as fully independent living spaces. They’re an excellent choice if you’d like to use the unit as a rental, offering privacy for both you and your tenant.
Interior ADU
An interior ADU is created by converting an existing space within your home—such as an attic, basement, or spare room. While they may be smaller, these units often require significant remodeling to ensure they can operate as independent living spaces. The advantage is that you can transform unused areas without expanding your property’s footprint.
Attached ADU
These units connect directly to your main home but maintain their own entrance. They may be built above an existing structure or added on as an extension. Attached ADUs generally require less remodeling than interior units and work well for home offices, guest suites, or extra family space.
Add room, comfort, and worth.
Your dream ADU, built on time and on budget
Why Build Your ADU With Us?
Choosing the right team for your ADU project brings peace of mind. With W and W Builders Group, you’re partnering with a trusted ADU builder known for expertise, personalized service, and full support from start to finish.
From our very first conversation, we take the time to understand your lifestyle and vision so we can create an ADU that aligns seamlessly with your goals. Our team guides you through every stage—blueprinting, permits, design, and construction—with meticulous attention to detail.
Our dedication to quality and your satisfaction speaks for itself. At W and W Builders Group, you’re never just a project—you’re part of the family.
➡️ Contact us today to schedule your complimentary consultation, get your ADU questions answered, and take the first step toward your dream ADU!
Read What Our Customers Say:
EXCELLENT Based on 37 reviews José Fleitas2025-08-31Trustindex verifies that the original source of the review is Google. I recently hired W AND W BUILDERS to address a few damaged floorboards in my living room, and I was pleased with the results. The team was on time and showed great professionalism throughout the process, which was a relief given my tight schedule. While the prices were reasonable, the quality of the repair work was impressive, making it a worthwhile investment! Iris Garrido2025-08-25Trustindex verifies that the original source of the review is Google. I recently had W and W Builders Group handle a siding repair on my home, and I was quite satisfied with the results. The team was professional and addressed the issue efficiently, replacing the damaged panels with precision. The pricing was reasonable for the quality of work provided, with no hidden costs involved. Overall, the process was straightforward, and I appreciated their attention to detail! may micha2025-08-02Trustindex verifies that the original source of the review is Google. They just completed my brand new kitchen remodel and have never been so happy with the results. From going above and beyond as far as communication and work, so pleased. Matt Chase2025-07-30Trustindex verifies that the original source of the review is Google. W and W handled a kitchen renovation for my parents (who can't seem to figure out the whole google review thing) so here we are: My parents were thrilled with the work and professionalism. Since I'm not physically there myself, I'll let the photos my parents took do the talking! Marie Ben ami2025-07-15Trustindex verifies that the original source of the review is Google. we did a full gut renovation on our home in Palo Alto and couldn’t be happier with how it turned out. W and W Builders handled everything from demo to finishes and made what could’ve been a stressful process feel really smooth. They knew each and every inspector and had a great working relationship with them, which helped move things along without delays. The team was on it every step of the way showed up, communicated clearly, and delivered quality work. Definitely recommend if you’re doing a major remodel and want people you can actually trust. Rotem Avitan2025-07-14Trustindex verifies that the original source of the review is Google. Can’t say enough good things!!! W and W came in, got to work, and never slowed down. No drama, no surprises. Just a solid crew that actually cares about doing a good job. They deserve this review and so much more! Highly recommend them for any high-end master bathroom remodeling project. Mercedes Foster2025-07-08Trustindex verifies that the original source of the review is Google. We did a full gut remodel with w and w builders and the transformation is incredible. Every room was thoughtfully designed and executed with high-quality workmanship. The crew was punctual, professional, and very easy to work with. Our house feels brand new. A+! Deborah Martinez2025-05-29Trustindex verifies that the original source of the review is Google. We hired W and W Builders Group to remodel our bathroom, and they did an amazing job. Magen was great to work with. super organized and always kept us updated. The crew was professional, the work was high quality, and everything was finished on time. We’re really happy with how it turned out and would definitely use them again. Paul Hudson2025-05-19Trustindex verifies that the original source of the review is Google. We just finished a full home remodel with W AND W Builders Group, and the experience was honestly great from start to finish. We updated everything: kitchen, bathrooms, flooring, electrical, plumbing- you name it. Gil, our project manager, was amazing. He stayed on top of every detail, always kept us informed, and really made sure things ran smoothly. Every crew that came through was professional, respectful, and did high-quality work. What really stood out was how organized the whole process was- no chaos, no guessing, and no surprises on pricing. The end result turned out even better than we hoped and we’re so glad we went with W and W. Would definitely recommend them to anyone taking on a big remodel.
You got questions, we got answers.
FAQ's
ADU Construction Timeline: How Long Does It Take?
The length of time it takes to build an ADU depends on the size, scope, and type of unit you’re creating. Since ADU construction involves multiple steps, each stage affects the overall timeline.
Planning – This stage generally takes between 2–4 months. It includes the initial consultation, walk-throughs, design development, and creating the scope of work proposal.
Permitting – The permitting process can vary greatly depending on project complexity. Our team prepares the architectural plans based on your goals, submits them for review, manages revisions, and follows up to keep your project moving smoothly.
Construction – The build phase depends on the size and complexity of the ADU. Beyond construction itself, this stage includes installing plumbing, electrical, and other essential systems required for a fully functioning living space.
Overall Timeline – Every ADU project is unique, so the total duration can vary significantly. Your dedicated project manager will provide clear expectations and regular updates, ensuring you understand the schedule and can plan accordingly.
How Much Does an ADU Project Typically Cost?
The cost of an ADU project can vary significantly depending on the size, design, finishes, and type of ADU you choose—whether it’s detached, attached, or interior. On average, projects can range from $150,000 to $400,000 or more, with smaller conversions generally on the lower end and larger, ground-up builds on the higher end.
Key factors that impact the overall price include:
Size and layout of the ADU
Structural changes required
Quality of finishes and materials
Plumbing, electrical, and mechanical needs
Permit and city fees
When you work with our team, you’ll receive a detailed scope of work and transparent pricing so you know exactly what to expect. We also guide you in making cost-effective choices without sacrificing quality, ensuring your ADU is a smart investment that adds long-term value to your property.
What Are the Different Types of ADUs You Can Build?
There are three main types of ADUs, each offering unique benefits depending on your needs:
Detached ADU – A stand-alone structure built separately from the main home. Great for rental income, guest houses, or private living spaces, these provide the most independence and privacy.
Attached ADU – Connected to the main home but with its own entrance. These can be built as extensions or above an existing structure, making them ideal for extra family space or a home office.
Interior ADU – Created by converting existing space inside the home, such as a basement, attic, or unused rooms. While these often require more remodeling, they’re a great way to maximize square footage without expanding the property footprint.
Each type can be customized to fit your goals—whether you’re looking for additional income, family space, or long-term investment value.
Will Building a New ADU Add Value to My Property?
Yes—adding an ADU is one of the smartest ways to increase property value. A well-designed ADU not only expands your usable living space but also creates opportunities for rental income, multi-generational living, or flexible guest accommodations. Buyers often see ADUs as a major advantage, which can make your property more attractive on the market and boost resale value.
What Are My Options for Financing an ADU?
Financing a new ADU can be approached in several ways, depending on your budget and long-term goals:
Home Equity Loan or Line of Credit (HELOC): Allows you to borrow against the equity you’ve already built in your home.
Cash-Out Refinance: Replaces your existing mortgage with a larger one, giving you funds to cover ADU construction.
Construction Loan: Short-term financing that covers building costs, which can later be converted into a traditional mortgage.
Personal or Renovation Loan: Flexible options for smaller projects or homeowners who prefer not to use home equity.
Special ADU/Green Financing Programs: Some lenders and local governments offer tailored loans or incentives for accessory dwelling units.
Our team can help you explore which option best suits your situation, ensuring your ADU is not only a functional space but also a smart financial investment.
What’s the Best Way to Plan for ADU Construction?
Successful ADU construction starts with thoughtful planning. Here are the key steps:
Define Your Goals: Decide how you’ll use the ADU—rental income, guest space, or family living.
Set a Budget: Factor in design, permits, construction, and finish materials.
Explore Design Options: Work with a designer or builder to create a layout that fits your lifestyle and property.
Understand Regulations: Research local zoning, setback requirements, and building codes before moving forward.
Hire the Right Team: Choose an experienced design-build contractor who can manage the entire process, from permits to construction.
With expert guidance, your ADU project can move smoothly from concept to completion, ensuring you get a space that adds both function and value to your property.
Contact our team!
Send us a message about your project, and one of our representatives will get back to you