ADUs & Garage Conversions
ADU Construction & Garage Conversions for Silicon Valley & Peninsula Homeowners
Create More Space. Unlock More Possibilities
W&W Builders Group designs, permits, and builds ADUs and garage conversions across Silicon Valley and the Peninsula. Detached ADUs, attached ADUs, garage conversions, and JADUs, all managed in-house by one project manager with 15+ years of local permit experience. Design, permits, and construction under one roof. Transparent pricing. No surprise change orders.
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ADU & Garage CONVERSIONS SILICON VALLEY
Create More Space. Unlock More Possibilities
Whether you’re building a detached ADU, converting a garage, or planning a JADU, our design-build team handles everything from planning and permits to construction and final completion.
An Accessory Dwelling Unit (ADU) is one of the most versatile investments a homeowner can make. Whether you’re creating space for aging parents, adult children, guests, rental income, a private home office, or future flexibility, an ADU can add both functionality and long-term value to your property.
As ADU regulations continue to evolve throughout California, more homeowners are taking advantage of opportunities to build detached ADUs, attached ADUs, garage conversions, and backyard cottages that support their changing needs and goals.
At W&W Builders Group, we help homeowners throughout Silicon Valley and the Peninsula navigate every stage of the ADU process- from feasibility studies and site planning to design, permits, construction, and final completion.
An Accessory Dwelling Unit (ADU) is one of the most versatile investments a homeowner can make. Whether you’re creating space for aging parents, adult children, guests, rental income, a private home office, or future flexibility, an ADU can add both functionality and long-term value to your property.
As ADU regulations continue to evolve throughout California, more homeowners are taking advantage of opportunities to build detached ADUs, attached ADUs, garage conversions, and backyard cottages that support their changing needs and goals.
At W&W Builders Group, we help homeowners throughout Silicon Valley and the Peninsula navigate every stage of the ADU process- from feasibility studies and site planning to design, permits, construction, and final completion.
“The right ADU doesn’t just add square footage- it creates flexibility, opportunity, and lasting value for years to come.”
Magen
Magen Peretz
Co-Founder & Senior Project Manager
Co-Founder & Senior Project Manager
W&W Builders Group
15+ Years of Experience
ADU building and residential construction across Silicon Valley and the Peninsula.
Design-Build Under One Roof
Design, planning, permits, pricing, and construction coordinated through one team.
5-Star Reputation Across the Board
Trusted by homeowners with top-rated reviews across Google, Houzz, Yelp, and Angi, with countless client references available.
Dedicated Project Management
One clear point of contact from site feasibility through final city inspection.
Licensed & Insured
California licensed general contractor (CSLB #1037294) serving homeowners across Silicon Valley.
BEFORE & AFTER
ADU Projects Built Around Real Needs
Every ADU starts with a goal.
For some homeowners, it’s creating space for aging parents or adult children. For others, it’s generating rental income, accommodating guests, adding a private home office, or making better use of an underutilized backyard or garage.
The projects below showcase real ADU transformations completed throughout Silicon Valley and the Peninsula. Each one was designed around the homeowner’s unique needs, property constraints, and long-term goals.
For some homeowners, it’s creating space for aging parents or adult children. For others, it’s generating rental income, accommodating guests, adding a private home office, or making better use of an underutilized backyard or garage.
The projects below showcase real ADU transformations completed throughout Silicon Valley and the Peninsula. Each one was designed around the homeowner’s unique needs, property constraints, and long-term goals.
📍 Santa Clara, CA
Detached ADU
This 800 SF detached ADU features 2 bedrooms, 1 bathroom, and a bright open-concept layout designed for modern living. Oak-tone prefab shaker cabinetry, prefab quartz countertops with a matching quartz backsplash, and wide-plank engineered hardwood flooring create a warm and inviting atmosphere. The bathroom is finished with a fluted/ribbed vanity, brushed brass fixtures, and large-format porcelain tile for a clean, contemporary look.
📍 San Jose, CA
800 SF Detached ADU
This modern 800 SF detached ADU features an open-concept living and dining area, custom recessed niches, a built-in media wall, and expansive sliding glass doors that fill the home with natural light. The kitchen showcases flat-panel Italian-style cabinetry, quartz slab countertops with a matching full-height backsplash, and stainless steel appliances. Large-format porcelain tile flooring runs throughout, while the bathroom features glossy subway-style wall tile, an integrated shower bench, a linear drain, and a custom niche.
Highlights
Highlights
📍 Menlo Park, CA
850 SF Ground-Up Detached ADU
Built from the ground up, this 850 SF detached ADU features 1 bedroom, 1 bathroom, and a bright open-concept living, dining, and kitchen area. The home showcases vaulted ceilings, flat-panel cabinetry, quartz countertops with a full-height slab backsplash, engineered wood flooring, and expansive Milgard sliding glass doors that maximize natural light and indoor-outdoor living. The spacious bathroom includes large-format tile, a custom shower bench, and built-in niche for a clean, modern aesthetic.
WHAT TYPE OF ADU IS RIGHT FOR YOUR PROPERTY?
ADU Solutions Designed Around Your Goals
Not every property—and not every homeowner—has the same goals. Some homeowners are focused on rental income. Others want a private space for family members, guests, or future flexibility. Our team helps homeowners evaluate the best ADU option based on their lot, budget, local regulations, and long-term plans.
Detached ADU
A fully independent structure built separately from the primary residence, offering maximum privacy and flexibility.
Attached ADU
A new living space connected to the primary residence while maintaining its own entrance and functionality.
Garage Conversions
Transform an existing garage into a comfortable and efficient living space while minimizing new construction costs.
Junior ADUs (JADUs)
A smaller living unit created within the existing home, often providing a cost-effective solution for additional living space.
Custom ADU Solutions
Every property is different. We help homeowners explore creative solutions tailored to their specific site, goals, and local zoning requirements.
WHY HOMEOWNERS CHOOSE W&W
Building An ADU Is Complex. We Help Simplify The Process.
Building an ADU involves far more than construction alone. Site constraints, zoning requirements, permit approvals, utility connections, design decisions, and budgeting all play a critical role in the success of the project.
At W&W Builders Group, we guide homeowners through every phase of the process- from feasibility and planning to permits, construction, and final completion- creating a smoother and more organized experience from start to finish.
At W&W Builders Group, we guide homeowners through every phase of the process- from feasibility and planning to permits, construction, and final completion- creating a smoother and more organized experience from start to finish.
What Homeowners Can Expect
“Turning our garage into a rental ADU was a big decision, and I'm so glad we went with Wand W Builders Group. Their team helped with everything from architectural plans and permits to design and final construction. The result is a modern stylish unit that's already generating rental income.”
Victoria Young
- Victoria Young, Client
OUR PROCESS
A Clear ADU Process From Concept To Completion
Building an ADU involves much more than construction alone. Site conditions, local regulations, permits, utility connections, design decisions, and careful planning all play an important role in the success of the project.
Our design-build process helps homeowners navigate every stage with one team guiding the project from the initial feasibility review through final completion.
Our design-build process helps homeowners navigate every stage with one team guiding the project from the initial feasibility review through final completion.
01
Discovery & Property Evaluation
Every ADU project begins with understanding your goals and evaluating the property’s potential. We review your site, discuss intended use, explore budget considerations, and identify opportunities and constraints before moving forward.
02
Design & Feasibility Planning
Our team develops preliminary layouts, floor plans, and design concepts while evaluating setbacks, lot conditions, utility access, and local ADU requirements.
03
Budget & Project Planning
Once the scope is established, we provide detailed pricing, construction planning, and project expectations so homeowners can move forward with confidence.
04
Plans, Engineering & Permits
We coordinate architectural plans, engineering, permit submissions, and city reviews while helping navigate local ADU regulations and approval requirements.
05
Construction
With permits approved, our team begins construction while managing scheduling, inspections, communication, quality control, and day-to-day project progress.
06
Final Walkthrough & Move-In Ready
Before completion, we review final details, perform quality checks, complete inspections, and ensure the ADU is ready for occupancy and everyday use.
architectural design, drafting, and 3D planning
See Your ADU Before Construction Begins
Building an ADU is a significant investment, and many homeowners want to understand exactly how the space will look, feel, and function before construction starts.
Our design-build process helps homeowners visualize their future ADU through thoughtful planning, detailed floor plans, and realistic 3D renderings. Whether you’re building a detached ADU, garage conversion, attached ADU, or backyard cottage, we help bring the vision to life before breaking ground.
From layout optimization and space planning to material selections and exterior design, every detail is considered to help create a living space that supports your goals while maximizing the potential of your property.
Our design-build process helps homeowners visualize their future ADU through thoughtful planning, detailed floor plans, and realistic 3D renderings. Whether you’re building a detached ADU, garage conversion, attached ADU, or backyard cottage, we help bring the vision to life before breaking ground.
From layout optimization and space planning to material selections and exterior design, every detail is considered to help create a living space that supports your goals while maximizing the potential of your property.
FREE ADU DESIGN & 3D RENDERING
$1000
Value Included
Move forward with your ADU project and receive complimentary design guidance and a 3D rendering as part of our design-build process.
Design Inspiration
“The best ADU projects begin with a clear vision and a plan to bring it to life.”
RECENT PROJECTS
Recent ADU & Garage Conversion Projects
Detached ADU
Santa Clara
850 SF Ground-Up Detached ADU
Menlo Park
800 SF Detached ADU
San Jose
Trusted by Homeowners Across Silicon Valley
We are proud to maintain 5-star ratings across Google, Yelp, Houzz, and other trusted platforms. But do not take our word for it. See what real homeowners have to say about their experience working with W&W Builders Group.
SERVING SILICON VALLEY & THE PENINSULA
Local ADU Experts
W&W Builders Group proudly serves homeowners throughout Silicon Valley and the Peninsula, including San Jose, Palo Alto, Mountain View, Los Gatos, Redwood City, San Mateo, and surrounding communities. Our team provides planning, permitting, design, and construction services to help homeowners navigate the ADU process with confidence.
SILICON VALLEY
THE PENINSULA
Planning an ADU Project?
Schedule a free consultation to discuss your property, goals, budget, and ADU possibilities.
FAQ
Frequently Asked Questions
What is the difference between a detached ADU and a garage conversion?
A detached ADU is a brand-new standalone structure built in the backyard on its own foundation, completely separate from the main home. A garage conversion takes an existing attached or detached garage and transforms the interior into a fully livable space, adding a kitchen, bathroom, and private entrance to what was already there. Because the foundation and structure of the garage already exist, garage conversion services typically cost less and permit faster than a detached new build. W&W Builders Group builds both types across Silicon Valley and helps homeowners determine which option makes the most sense for their specific lot and budget.
How much does an ADU cost in Silicon Valley?
ADU building costs in Silicon Valley depend on the type of ADU, the lot conditions, the finish level, and the city's permit fees. A garage conversion in Santa Clara or Mountain View typically costs less than a detached backyard ADU in Palo Alto or Los Altos, where lot conditions and permit timelines can add to the scope. Premium detached ADUs in Los Altos and Cupertino can approach $350,000 to $400,000. W&W Builders Group reviews the site, the applicable city rules, and the full construction scope before producing a line-item proposal so homeowners understand the complete investment before any work begins.
How long does it take to build an ADU in San Jose or Palo Alto?
ADU building timelines in Silicon Valley depend on the type of ADU, the city's permit review process, and the construction scope. San Jose's pre-approved plan program can compress residential ADU plan review from 4 to 6 weeks down to 1 to 2 weeks for qualifying lots, which is one of the fastest permit paths available anywhere in the Bay Area. Palo Alto's permit process for ADUs can take longer, particularly for projects near Eichler overlay neighborhoods. W&W Builders Group maps the permit path and construction schedule at the start of every ADU project so homeowners know the realistic timeline before design begins.
Are garage conversions subject to setback requirements in Silicon Valley?
No. Garage conversions are fully exempt from setback requirements under California state law, which makes them one of the most practical ADU types on smaller Silicon Valley lots where a detached new build might not fit within the required 4-foot rear and side setbacks. W&W Builders Group reviews setback conditions during the initial site feasibility review for every ADU project, so homeowners understand their options before design decisions are made.
Do I need to live on the property to build an ADU in Silicon Valley?
No. California's AB 976, which took effect on January 1, 2024, permanently eliminated owner-occupancy requirements for ADUs statewide. Silicon Valley homeowners can now build an ADU as a long-term rental unit, a multigenerational suite, or a future property investment without the prior requirement of living on the lot. The only significant local restriction to be aware of is in Palo Alto, where short-term ADU rentals are prohibited under local rules, with a 30-day minimum lease required and a deed restriction filed at permit.
What is a JADU and how is it different from a regular ADU?
A JADU, or Junior Accessory Dwelling Unit, is a secondary unit carved out of the existing home's interior floor plan and is capped at 500 square feet under California state law. JADUs must share at least one wall with the primary residence and require an efficiency kitchen rather than a full kitchen. They are one of the fastest and most affordable ADU types because they use the existing structure, but they are smaller and have more restrictions than a detached ADU or garage conversion. W&W Builders Group builds JADUs across Silicon Valley alongside all other ADU types as part of its full design-build ADU building service.
Can W&W Builders Group use San Jose's pre-approved ADU plan program?
Yes. W&W Builders Group uses the City of San Jose's pre-approved ADU plan program on qualifying projects, which compresses plan review from the standard 4 to 6 week window down to 1 to 2 weeks. San Jose has issued nearly 3,000 ADU permits and seen 1,451 completions since launching the program in 2019. For homeowners with qualifying lots, this is one of the most effective ways to accelerate the ADU building process. W&W Builders Group evaluates whether a pre-approved plan works for the lot during the feasibility review and designs from scratch on lots where pre-approved plans do not apply.
What size ADU can I build in San Jose or on the Peninsula?
In San Jose, a detached ADU can be up to 1,000 square feet on lots under 9,000 square feet and up to 1,200 square feet on lots 9,000 square feet or larger. Attached ADUs are capped at 800 square feet or 50 percent of the primary residence, whichever is smaller. JADUs are capped at 500 square feet statewide. ADUs under 750 square feet qualify for statewide impact fee waivers, which can reduce upfront project costs. Peninsula city rules vary, and W&W Builders Group verifies the applicable size limits for the specific city and lot at the start of every ADU project.
Does an ADU add value to my Silicon Valley property?
Yes. A permitted, built ADU adds assessed value to your property and increases its appeal to future buyers, particularly in Silicon Valley, where housing density and rental demand remain high. A well-built backyard ADU or garage conversion in Santa Clara, Sunnyvale, or Mountain View can produce monthly rental income that offsets carrying costs while adding a permanent, insurable structure to the property. W&W Builders Group builds every ADU to the same quality standard as the main home, with proper permits, inspections, and finish work, so the unit is both rentable and appraised as a genuine asset.
Who manages my ADU once construction starts?
W&W Builders Group assigns one dedicated project manager to every ADU and garage conversion project, from the initial site feasibility review through the final city inspection. That project manager coordinates the design, permit submittals, trade scheduling, structural inspections, utility connections, and all homeowner communication from start to finish. For Silicon Valley homeowners building a 6 to 12 month ADU project, having one clear point of contact is what keeps the work on track and the permit process moving. One family. One project manager. From sketch to keys.
CONTACT
Ready to Build an ADU or Convert Your Garage?
Schedule a free consultation to discuss your ADU or garage conversion project, site conditions, city rules, and what W&W Builders Group can build on your lot.
