Transform Your Property with Professional ADU Construction
Homeowners across San Jose, CA are realizing that adding an accessory dwelling unit is one of the most rewarding investments they can make. ADU construction provides a flexible new living space on your existing property — whether you want to generate rental income. Brother & Brother Builders has guided hundreds of local homeowners bring these projects to life with craftsmanship and integrity.
The interest in ADU construction has grown rapidly in recent years, and it's easy to understand why. California state law has streamlined permitting for homeowners to build these secondary units, and local municipalities like San Jose have encouraged the trend as a way to increase density responsibly. Whether you're building a detached backyard cottage, a garage conversion, or an attached addition, ADU construction offers greater control over how your property works.
At Brother & Brother Builders, we apply deep hands-on experience to every ADU construction build. Our team knows the San Jose building codes, the engineering details, and the planning steps that make an ADU truly livable. If you've been thinking about what ADU construction could do for your property, this guide explains everything you need to know.
What Is an ADU Build?
ADU construction refers to click here 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 — equipped with a kitchen, bathroom, sleeping area, and its own access point — that sits on the same property as a primary residence. ADU construction comes in multiple configurations, including detached backyard units, attached additions, garage conversions, and even basement or interior conversions.
Mechanically, everything kicks off with a thorough property evaluation, where our professionals evaluate setbacks, zoning, utility access, and structural feasibility. From there, design plans are prepared and submitted to the local building department. Once approvals are in place, ADU construction moves into the physical build phase — which covers everything from foundational work, framing, mechanical systems, weatherproofing, and interior finishing. The result is a fully functional living unit attached to or separate from your main home.
What separates excellent ADU construction from an average project is the attention to detail at every stage. Products need to be chosen to match the primary home's aesthetic. Systems like plumbing and electrical must be designed to handle full-time occupancy. Brother & Brother Builders approaches every build with the same professional rigor we use on major custom home projects.
Key Reasons to Choose ADU Construction
- Increased Property Value — ADU construction delivers real market value to your property, often returning more than the build cost when it's time to sell.
- Monthly Cash Flow — A completed ADU is leasable as a long-term rental or short-term vacation unit, providing a consistent income stream for the homeowner.
- Multi-Generational Living — ADU construction offers family members a self-contained residence without leaving the property.
- Design Flexibility — From open-plan one-bedrooms, ADU construction can be tailored to your household's priorities.
- Faster Permitting in California — Recent state legislation has cut down the barriers and delays associated with ADU construction, making the process that is faster and less expensive than ever before.
- Sustainable Land Use — Building an ADU works within your current footprint instead of expanding urban sprawl, which aligns with sustainability goals.
- Privacy for All Residents — Unlike a bedroom addition, ADU construction creates a truly separate unit where occupants have full privacy.
- Long-Term Investment Security — A well-built ADU continues to produce returns for the long haul by offering both usable housing and equity growth.
The ADU Construction Procedure Step by Step
- Initial Property Assessment and Feasibility Review — Our team visits your property to evaluate setbacks, lot coverage limits, and utility connections. This phase answers exactly what can be built before any time is invested in drawings.
- Custom Design and Architectural Planning — Licensed architects and designers create comprehensive blueprints tailored to your needs. Layouts are carefully considered to create practical, comfortable living.
- Filing for Building Permits — ADU construction in San Jose involves filing drawings to the city's building department for sign-off and verification. We manage this entire process on your behalf, resolving any revision requests promptly.
- Excavation and Foundation Installation — Once permits are approved, on-site work kicks off. This involves leveling and prepping the ground, pouring the concrete foundation, and establishing utility connections.
- Framing, Roofing, and Exterior Work — The structural frame is erected followed by roofing, siding, windows, and exterior doors. At this stage, the ADU transforms from a concept to a building.
- Mechanical, Electrical, and Plumbing Installation — Certified technicians install the water supply, drain lines, and electrical panel that make the ADU ready for occupancy. Inspections are completed at designated stages throughout ADU construction.
- Interior Completion and City Sign-Off — Trim, appliances, tile, and lighting are installed and finished to the approved plan. A final city inspection grants legal occupancy status and your new space is cleared for use.
Who Is a Right Fit for ADU Construction?
People who see the greatest return from ADU construction typically fall into a few recognizable groups. If you have a residential property with enough lot space to meet setback requirements, you're already well-positioned. Homeowners looking to generate income through rental are among the most financially driven ADU construction clients, along with families supporting elderly parents.
ADU construction also suits someone who runs a small business and wants a private work environment that is distinct 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.
Homeowners who may want to pause and evaluate include properties with significant setback limitations. Very small lots or properties with easements may require additional review. Our experts will evaluate each property on its own merits to advise you on what's feasible.
ADU Construction FAQ
How long does ADU construction generally 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. The approval phase alone can take two to four months in San Jose, so beginning the process sooner rather than later is wise. Simpler garage conversions often finish in the lower end of the range, while larger new construction ADUs take longer to complete.
What does ADU construction usually run in terms of budget?
Costs vary widely based on the type and size of the ADU. Locally, ADU construction typically ranges from $150,000 to $400,000 or more for a standalone backyard unit. Garage conversions tend to cost less, sometimes between $75,000 and $140,000. A precise cost projection can only be given after completing a formal feasibility evaluation.
Is ADU construction disruptive while it's underway?
How much the build affects daily life depends on whether you're converting existing space or building new. Detached backyard builds are generally the least intrusive, 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. We provide advance notice about upcoming work and timelines.
Do I need to vacate the property during ADU construction?
For the majority of homeowners, you are not required to vacate your main home during ADU construction. Most builds are designed so that you remain on the property throughout the construction timeline. There are edge cases if significant structural connections require temporary shutoffs in ways that temporarily impact livability. Our construction supervisors 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 — indefinitely with proper upkeep. Longevity is tied to the quality of materials used, how well routine maintenance is performed, and whether systems like roofing and plumbing are serviced regularly. We select high-quality components and follow all code requirements to protect your investment for the long haul.
ADU Construction for Local Homeowners
San Jose's neighborhoods offer a wide range of property types that are perfectly suited for ADU construction. Residents in the Rose Garden district often discover their properties are well configured for ADU builds. The Berryessa area are seeing more homeowners add secondary units as housing demand rises. From neighborhoods near the Guadalupe River Park corridor to those near Branham Lane, 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. Location near major arterials like Story Road or Tully Road can impact the design approach for a given ADU project. Our familiarity with these local conditions means more accurate timelines and budgets from the first meeting to the final inspection.
Schedule Your ADU Construction Consultation Today
When you want to explore what an ADU could look like on your lot, Brother & Brother Builders is the team to call. Our experts offer years of hands-on experience in ADU construction including all types of project types — from simple garage conversions to multi-room backyard residences. The process begins with a thorough and honest property review where we listen to your goals and give you a realistic picture of what the project will involve.
Get in touch with our office to set up your consultation. Even if you're just exploring the idea, we're glad to answer questions, share examples of our work and give you the clarity you need to move forward. This type of project is a meaningful commitment — and we're committed to helping you get it right.
Brother & Brother Builders | 3109 Stevens Creek Boulevard | San Jose CA 95117 | (888) 412-2632