Transform Your Property with Quality ADU Construction
Property owners throughout San Jose, CA are discovering that adding an accessory dwelling unit is one of the most practical investments they can make. ADU construction provides a flexible new living space on your existing property — whether you want to house a family member. Brother & Brother Builders has helped hundreds of local homeowners see these visions to life with precision and integrity.
The interest in ADU construction has surged in recent years, and it's not hard to see why. California state law now makes it easier for homeowners to build these secondary units, and local municipalities like San Jose have embraced the trend as a way to expand the housing supply. Whether you want to build a detached backyard cottage, a garage conversion, or an attached addition, ADU construction provides increased control over how your property works.
At Brother & Brother Builders, we draw on extensive hands-on experience to every ADU construction job. Our team understands the local permitting process, the engineering requirements, and the aesthetic decisions that make an ADU functional. If you've been thinking about what ADU construction could do for your property, this guide covers everything you need to know.
What Is ADU Construction?
ADU read more construction involves the process of engineering, filing for, and completing an accessory dwelling unit on a residential property. An accessory dwelling unit is a complete living space — including a kitchen, bathroom, sleeping area, and its own entryway — that exists on the same lot as a primary residence. ADU construction comes in multiple configurations, including detached backyard units, attached additions, garage conversions, and even below-grade dwelling units.
Mechanically, everything kicks off with a comprehensive review of your lot, where our builders evaluate lot dimensions, existing structures, soil conditions, and local code requirements. From there, design plans are prepared and submitted to the city for permit approval. Once approvals are in place, ADU construction transitions to the physical build phase — which covers everything from foundational work, framing, roofing, plumbing, electrical, insulation. The result is a move-in-ready living unit adjacent to or detached from your main home.
What separates excellent ADU construction from an average project is the depth of planning at every stage. Products need to be chosen to align with the neighborhood's character. Systems like plumbing and electrical must be designed to handle full-time occupancy. Brother & Brother Builders handles every ADU construction job with the same technical discipline we use on major custom home projects.
Key Benefits ADU Construction
- Boosted Home Equity — ADU construction contributes significant market value to your property, often generating strong equity gains when it's time to sell.
- Rental Income Potential — A completed ADU can be rented as a long-term rental or short-term vacation unit, creating ongoing passive income for the homeowner.
- Space for Loved Ones — ADU construction gives aging parents a private, independent living space without losing proximity to the family.
- Customization Options — From modern studio layouts, ADU construction is adaptable to your specific needs.
- Streamlined Approval Process — Recent state legislation has minimized the red tape associated with ADU construction, creating a path that is faster and more cost-efficient than ever before.
- Efficient Use of Your Lot — Building an ADU works within your current footprint instead of consuming open land, which aligns with sustainability goals.
- Privacy for All Residents — Unlike a bedroom addition, ADU construction produces a fully self-contained unit where residents have their own space.
- Lasting Financial Benefit — A well-built ADU remains an asset for the long haul by offering both functional space and financial upside.
The ADU Construction Journey Step by Step
- Initial Property Assessment and Feasibility Review — Our experts review your property to determine what type of ADU is allowed and where it can be placed. This step tells you exactly what can be built before any money is spent on design.
- Architectural Drafting and Space Planning — Licensed architects and designers create detailed floor plans based on your goals. Space is thoughtfully allocated to create practical, comfortable living.
- Permitting and City Approval — ADU construction in San Jose demands documentation to the city's building department for review and approval. Our team handles all submissions on your behalf, resolving any revision requests promptly.
- Ground Prep and Structural Base — Once permits are approved, on-site work kicks off. This involves leveling and prepping the ground, pouring the concrete foundation, and setting up utilities.
- Framing, Roofing, and Exterior Work — Framing is completed followed by weatherproofing and exterior finish materials. During this step, the ADU transforms from a concept to a building.
- Interior Systems and Infrastructure — Licensed subcontractors install the plumbing lines, electrical wiring, and HVAC systems that make the ADU ready for occupancy. Every system is reviewed at required milestones throughout ADU construction.
- Interior Finishing and Final Inspections — Countertops, hardware, finishes, and fixtures are installed and finished to the agreed design. A closing municipal review grants legal occupancy status and the unit is officially approved for use.
Who Is a Right Fit for ADU Construction?
Property owners who are best suited from ADU construction often belong to a few common profiles. If you are a homeowner with enough lot space to meet setback requirements, you're already a strong candidate. Homeowners hoping to offset mortgage costs through rental are among the most motivated ADU construction clients, along with families accommodating adult children who need housing.
Another strong candidate is someone who runs a small business and wants a private work environment that remains away from your family's daily life. Real estate-minded homeowners who already own residential properties are also a natural fit for ADU construction, since the long-term value is proven.
Situations where ADU construction may not be the best first step include sites with unusual utility access challenges. Parcels in historic districts or HOA-restricted communities may require additional review. Brother & Brother Builders reviews each property case by case to advise you on what's feasible.
ADU Construction Frequently Asked Questions
How long does ADU construction typically take from start to finish?
The complete duration for ADU construction typically ranges from six to fourteen months, based on the project scope and how quickly approvals come through. Permitting alone can take two to four months in San Jose, so planning ahead matters. Straightforward interior conversions may complete more quickly, while larger new construction ADUs require more time.
What does ADU construction typically cost?
Pricing depends on many factors based on the type and size of the ADU. In the San Jose area, ADU construction commonly costs $150,000 to $400,000 or more for a standalone backyard unit. Attached ADU additions often come in under, sometimes between $75,000 and $140,000. A detailed estimate can only be produced following a full site assessment.
Is ADU construction disruptive while it's underway?
The level of disruption depends on whether you're converting existing space or building new. New construction in the rear yard are typically less disruptive, since the crew operates at a distance from your living areas. Projects that connect to the main structure may involve some shared wall work during specific stages like framing or MEP rough-in. Our team communicates clearly about what to expect at each stage.
Do I need to move out during ADU construction?
Generally speaking, you won't have to vacate your house during ADU construction. The vast majority of projects are structured to allow you continue living in the home throughout the process. Certain situations could require a brief departure if significant structural connections require temporary shutoffs in ways that require short-term access disruption. Our project managers will flag these situations during the planning phase.
How long will an ADU built through professional ADU construction last?
An ADU constructed with quality materials should last as long as your primary home — typically 50 years or more. Longevity is tied to the standard of construction, whether the unit is properly cared for, and whether systems like roofing and plumbing are serviced regularly. We select commercial-grade materials and build to current California residential standards to ensure lasting performance.
ADU Construction for San Jose Homeowners
San Jose's neighborhoods offer a variety of property types that are perfectly suited for ADU construction. Residents in the Rose Garden district have found their lots are well configured for ADU builds. The Berryessa area are increasingly popular for ADU construction as multigenerational living becomes more common. Whether your property is near downtown San Jose, our team knows the permitting landscape well.
The City of San Jose's building department applies particular standards for ADU construction that require a builder familiar with local expectations. Access to infrastructure along thoroughfares like Monterey Road can affect how quickly permits are approved for a given ADU project. Our team's knowledge of this region's building landscape means more accurate timelines and budgets from kickoff through certificate of occupancy.
Start Your ADU Construction Planning Session Today
Should you be thinking about how to move forward with ADU construction, Brother & Brother Builders is ready to guide you. Our builders provide licensed expertise in ADU construction across a wide range of project types — from small attached additions to large custom detached cottages. The process begins with a comprehensive site assessment where we listen to your goals and provide an honest assessment of what the project will involve.
Reach out to our team to schedule a site visit. Whether you're in the early stages of planning, our team is happy to answer questions, share examples of our work and make sure you feel confident before committing. ADU construction is a significant investment — and we're committed to helping you get it right.
Brother & Brother Builders | 3109 Stevens Creek Boulevard | San Jose CA 95117 | (888) 412-2632