Planning to build an ADU in San Jose, CA but not sure where to start? W & W Builders Group is a trusted San Jose ADU contractor specializing in full-service design and construction. From initial planning and San Jose ADU permits to construction and final finishes, we manage the entire process so you don’t have to worry. Our in-house team of project managers, engineers, designers, and builders works together to deliver high-quality ADUs — whether you’re adding a rental unit, in-law suite, backyard cottage, or private guest space. For homeowners looking to expand their existing footprint instead, we also specialize in home additions in San Jose, offering seamless design-build solutions tailored to your property. With our experience, your San Jose ADU project is efficient, code-compliant, and built to last.
Learn more about our full ADU design and construction services.
A detached ADU in San Jose is built as a standalone structure, typically located in the backyard, and functions as a fully independent living space. This type of ADU is ideal for long-term or short-term rentals, as it provides maximum privacy for both homeowners and occupants. Because it is separate from the main residence, a detached ADU offers flexibility and strong rental potential.
An interior ADU in San Jose is created by converting existing space within the main home, such as a basement, attic, or unused room. While interior ADUs usually have a smaller footprint, they often require significant remodeling to meet ADU standards for independent living. This option allows homeowners to utilize underused space without expanding the home’s exterior or building a new structure.
An attached ADU in San Jose is connected directly to the primary residence while maintaining its own private entrance. These units can be built as an addition or above an existing structure and typically require less renovation than interior conversions. Attached ADUs work well as in-law suites, guest accommodations, home offices, or additional family living space.
Homeowners planning an ADU often explore additional upgrades such as kitchen remodeling in San Jose, bathroom remodeling, full home remodeling, or home additions to improve comfort and long-term value.
As an experienced ADU contractor in San Jose, we follow a structured, proven process designed to keep your project organized, predictable, and fully compliant with local zoning and building requirements. From the initial evaluation through final approval, our team manages every phase to ensure a smooth and stress-free ADU build.
We begin with a detailed consultation and on-site evaluation of your property. Our team reviews San Jose zoning regulations, setbacks, lot size, access, and existing conditions to confirm ADU feasibility. We also discuss your goals, budget, and intended use for the ADU to determine the best approach.
You receive a comprehensive proposal outlining the full scope of work, estimated project timeline, and budget expectations. This step ensures transparency, clear expectations, and a well-defined plan before moving forward with design and permitting.
Our designers and engineers develop custom ADU plans tailored to your property and lifestyle needs while fully complying with San Jose building codes and energy requirements. Each design focuses on efficient layouts, functionality, and long-term value.
We guide you through selecting finishes, fixtures, and materials that align with your design preferences, budget, and durability requirements. From flooring and cabinetry to appliances and exterior details, we help streamline decisions to keep the project on schedule.
We manage the entire permitting process, including plan submission, revisions, and coordination with the City of San Jose. Our experience with local approval processes helps minimize delays and keeps your ADU project moving forward efficiently.
Once permits are approved, construction begins. Our dedicated project managers oversee scheduling, trades, inspections, and quality control to ensure your ADU construction meets professional standards and stays on track.
After construction is complete, we conduct a detailed walkthrough with you and coordinate all final inspections. This step ensures every detail meets expectations and complies with San Jose code requirements.
Your ADU is complete, fully approved, and move-in ready. Whether you plan to use it as a rental unit, guest house, or additional living space, your new ADU is built for comfort, functionality, and long-term value.
Choosing the right ADU contractor in San Jose plays a critical role in how smoothly your project is approved, built, and completed. San Jose has specific ADU regulations, zoning requirements, setbacks, utility standards, and inspection processes that require detailed local knowledge. Working with a contractor experienced in San Jose’s approval system helps reduce delays, revisions, and unexpected costs.
As a local ADU contractor, we provide a streamlined design-build approach that keeps every phase of your project organized under one team—from initial planning and permitting to construction and final inspections. This integrated process allows for better communication, faster problem-solving, and a more predictable timeline.
Proven experience with San Jose ADU regulations and approvals
We understand local zoning, city review processes, and inspection requirements.
Design-build ADU services under one roof
Designers, engineers, and builders work together to simplify planning and execution.
Full permit and inspection coordination with the City of San Jose
We manage submissions, revisions, and scheduling to keep approvals moving forward.
Clear scopes of work and transparent pricing
Detailed proposals outline costs, timelines, and expectations before construction begins.
Dedicated project management from start to finish
One point of contact ensures clear communication and consistent oversight.
Quality craftsmanship built to meet long-term performance standards
Every ADU is constructed with durable materials, professional workmanship, and long-term value in mind.
Whether you’re planning a garage conversion, attached ADU, or detached ADU, choosing an experienced ADU contractor in San Jose ensures your project is built correctly, approved efficiently, and designed to add lasting value to your property.
The timeline for ADU construction in San Jose typically ranges from 6 to 12 months, depending on the scope of the project, ADU type, and the city approval process. Each phase plays a key role in determining how quickly your ADU can be completed.
Most San Jose ADU projects follow this general timeline:
Design & Planning (1–2 months): Finalizing layouts, architectural plans, and engineering while aligning with San Jose ADU regulations.
Permits & City Approvals (2–4 months): Submitting plans, responding to city comments, and securing required permits.
Construction Phase (3–6 months): Site preparation, foundation work, framing, utilities, inspections, and final finishes.
Factors such as detached vs. attached ADUs, garage conversions, lot conditions, and utility upgrades can affect the overall schedule. Projects that require minimal structural changes may move faster, while more complex builds can take longer.
At W & W Builders Group, we provide San Jose homeowners with a clear timeline upfront and manage each phase carefully to keep the project moving efficiently while maintaining quality and code compliance.
The cost of building an ADU in San Jose can vary significantly based on the size of the unit, design complexity, material selections, and the type of ADU you choose — whether it’s detached, attached, or an interior conversion. In general, San Jose ADU projects can range from approximately $150,000 to $400,000 or more, with smaller conversions typically on the lower end and larger, ground-up builds requiring a higher investment.
Several key factors influence the total cost of a San Jose ADU project, including:
ADU size and layout configuration
Structural modifications or foundation work
Quality of finishes and building materials
Plumbing, electrical, and mechanical system requirements
San Jose permit fees and city approval costs
When you work with W & W Builders Group, you receive a detailed scope of work and transparent pricing from the start, so there are no surprises along the way. Our team also helps San Jose homeowners make informed, cost-effective decisions that maintain quality while maximizing long-term value, ensuring your ADU is a smart and profitable investment.
In San Jose, homeowners can choose from several types of Accessory Dwelling Units (ADUs), depending on property layout, zoning rules, and intended use. Understanding the different ADU options available in San Jose can help you select the best solution for your space, budget, and long-term goals.
The most common types of ADUs you can build in San Jose include detached ADUs, attached ADUs, and interior ADUs. Each option offers unique advantages, whether you’re looking to create a rental unit, in-law suite, guest house, or additional living space.
Detached ADUs are standalone structures built separately from the main home and provide maximum privacy and flexibility. Attached ADUs are connected to the primary residence but include a private entrance, making them ideal for extended family or home offices. Interior ADUs are created by converting existing space within the home, such as a basement, garage, or spare room, allowing homeowners to add living space without expanding the home’s footprint.
Choosing the right ADU type in San Jose depends on factors such as lot size, existing structures, budget, and city regulations. Working with an experienced San Jose ADU contractor ensures your project is designed correctly, permitted efficiently, and built to meet all local requirements.
Yes — building an ADU in San Jose can significantly increase your property’s value when designed and constructed properly. ADUs are highly desirable in San Jose due to housing demand, rental potential, and the flexibility they provide homeowners.
A well-built ADU adds value in several ways. It creates additional livable square footage, which is one of the strongest drivers of property value. It also offers income-generating potential, whether through long-term rentals, short-term rentals (where permitted), or multi-generational living. Many buyers actively look for properties with existing, permitted ADUs, giving your home a competitive edge in the San Jose market.
The amount of value added depends on factors such as the type of ADU (detached, attached, or conversion), build quality, layout, and overall integration with the main residence. ADUs that are fully permitted, thoughtfully designed, and built with quality materials tend to deliver the strongest return on investment.
Working with an experienced San Jose ADU builder ensures your ADU is code-compliant, well-planned, and positioned to maximize both immediate usability and long-term property value.
Homeowners planning to build an ADU in San Jose have several financing options available, depending on their budget, property equity, and long-term goals. Choosing the right financing approach early can help keep your ADU project on track and aligned with your investment plans.
Common San Jose ADU financing options include home equity loans or HELOCs, cash-out refinancing, construction loans, and personal or home improvement loans. In some cases, homeowners may also explore specialized ADU financing programs or incentives available at the local or state level.
The best financing option often depends on the type of ADU, total project cost, and whether the ADU will be used for rental income, family living, or personal use. An experienced San Jose ADU contractor can help you understand how different financing choices may affect project scope, timeline, and overall costs.
At W & W Builders Group, we guide San Jose homeowners through the planning process and help coordinate their ADU design and construction in a way that aligns with their chosen financing strategy, ensuring a smooth and well-managed project from start to finish.
The best way to plan for ADU construction in San Jose is to start with a clear understanding of your goals, budget, and property conditions, while accounting for local zoning and permitting requirements. Early planning helps avoid delays and ensures your ADU is designed correctly from the start.
Key planning steps include determining how the ADU will be used — such as a rental unit, in-law suite, or guest space — reviewing San Jose ADU regulations, and evaluating your lot for size, access, utilities, and setbacks. Choosing the right ADU type (detached, attached, or conversion) also plays a major role in overall cost and timeline. In some cases, ADU projects are combined with home additions in San Jose to maximize usable living space efficiently.
Working with an experienced San Jose ADU contractor is one of the most important steps. A professional design-build team can guide you through feasibility, design, permits, and construction while keeping the project aligned with your budget and schedule.
At W & W Builders Group, we help San Jose homeowners plan ADU projects with a structured, end-to-end approach, providing clarity, coordination, and expert guidance at every stage of the process.
