Transform Your Property with Expert ADU Construction
Property owners throughout San Jose, CA are finding that adding an accessory dwelling unit is one of the smartest investments they can make. ADU construction provides a versatile new living space on your existing property — whether you want to create a private workspace. Brother & Brother Builders has guided hundreds of local homeowners turn these plans to life with skill and transparency.
The popularity of ADU construction has surged in recent years, and it's no mystery. California state law has streamlined permitting for homeowners to add these secondary units, and local municipalities like San Jose have encouraged the trend as a way to address housing needs. If you're planning a detached backyard cottage, a garage conversion, or an attached addition, ADU construction provides increased control over how your property serves your household.
At Brother & Brother Builders, we bring years of hands-on experience to every ADU construction job. Our team knows the San Jose building codes, the engineering considerations, and the aesthetic decisions that make an ADU beautiful. Should you want to learn about what ADU construction could mean for your property, this guide covers everything you need to know.
What Is the ADU Construction Process?
ADU construction involves the process of planning, approving, and constructing 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 entrance — that is located on the same parcel as a primary residence. ADU construction can take several forms, including detached backyard units, attached additions, garage conversions, and even interior space reconfigurations.
Mechanically, everything kicks off with a thorough property evaluation, where our professionals evaluate setbacks, zoning, utility access, and structural feasibility. From there, blueprints are prepared and submitted to the relevant municipal authority. Once the paperwork is cleared, ADU construction transitions to the physical build phase — which encompasses site preparation, framing, mechanical systems, weatherproofing, and interior finishing. The result is a move-in-ready living unit connected to or independent of your main home.
What sets quality ADU construction apart is the level of craftsmanship at every stage. Materials must be selected to match the primary home's aesthetic. Systems like wiring and water supply must be built for long-term residential demand. Brother & Brother Builders handles every ADU construction job with the same technical discipline we bring to full custom home projects.
Key Reasons to Choose 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.
- Revenue Generation — A completed ADU is leasable as a long-term rental or short-term vacation unit, generating steady monthly revenue for the homeowner.
- Multi-Generational Living — ADU construction gives aging parents a comfortable home of their own without moving to another neighborhood.
- Personalized Layouts — From modern studio layouts, ADU construction can be tailored to your household's priorities.
- Streamlined Approval Process — Recent state legislation has reduced the red tape associated with ADU construction, resulting in a timeline that is faster and more cost-efficient than ever before.
- Sustainable Land Use — Building an ADU uses your existing lot instead of consuming open land, which supports broader sustainability goals.
- Separate Entrances and Spaces — Unlike a bedroom addition, ADU construction produces a fully self-contained unit where tenants live autonomously.
- Long-Term Investment Security — A well-built ADU holds its value for the long haul by offering both livable square footage and monetary benefit.
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 stage clarifies exactly what ADU types will work before any time is invested in drawings.
- Architectural Drafting and Space Planning — Experienced draftspeople create comprehensive blueprints tailored to your needs. Space is thoughtfully allocated to optimize daily use.
- Permit Submission and Municipal Review — ADU construction in San Jose demands documentation to the city's building department for inspection and clearance. Our team handles all submissions on your behalf, resolving any revision requests promptly.
- Site Preparation and Foundation Work — Once permits are granted, on-site work kicks off. This involves leveling and prepping the ground, laying the structural base, and running initial plumbing and electrical conduits.
- Framing, Roofing, and Exterior Work — Walls and roof systems go up followed by weatherproofing and exterior finish materials. This phase, the ADU takes its visible shape.
- Mechanical, Electrical, and Plumbing Installation — Skilled tradespeople install the water supply, drain lines, and electrical panel that make the ADU fully functional. Inspections are completed at designated stages throughout ADU construction.
- Interior Finishing and Final Inspections — Flooring, cabinetry, fixtures, paint are installed and finished to your specifications. A last official inspection confirms the unit is code-compliant and the unit is officially approved for use.
Who Is a Strong Candidate for ADU Construction?
People who see the greatest return from ADU construction typically fall into a few recognizable groups. If you own a single-family home with enough lot space to meet setback requirements, you're already a strong candidate. Homeowners looking to generate income through rental are among the most common ADU construction clients, along with families accommodating adult children who need housing.
ADU construction also suits someone who works from home and wants a separate office or studio space that doesn't interfere with your family's daily life. Landlords and real estate investors who want to maximize their land are also prime candidates for ADU construction, since the return on investment is well-documented.
Situations where ADU construction may not be the best first step include lots that are below minimum size thresholds. Sites with underground infrastructure conflicts may require additional review. Our team can assess each property case by case to provide realistic options.
ADU Construction FAQ
How long does ADU construction typically take from start to finish?
The total process for ADU construction usually runs between six to fourteen months, depending on design complexity and city review schedules. The approval phase alone can take a significant portion of the overall timeline in San Jose, so planning ahead matters. Simpler garage conversions can move faster, while custom detached builds take longer to complete.
What does ADU construction cost in San Jose?
Budget requirements differ based on the type and size of the ADU. Locally, ADU construction typically ranges from $150,000 to $400,000 or more for a fully custom construction. Interior conversion projects often come in under, sometimes starting around $80,000 depending on scope. An accurate budget can only be developed after a thorough property review.
Is ADU construction intrusive while it's underway?
The level of disruption depends on whether you're converting existing space or building new. Standalone ADU projects are usually easier to live alongside, since the construction zone is separate. Projects that connect to the main structure may require temporary access during certain phases of construction. Brother & Brother Builders keeps you informed about upcoming work and timelines.
Do I need to leave my home during ADU construction?
For the majority of homeowners, you are not required to vacate your house during ADU construction. Most builds are designed so that you stay in your primary unit throughout the construction timeline. There are edge cases if major utility upgrades affect the main house in ways that briefly affect habitability. Our project managers will flag these situations during the pre-construction consultation.
How long will an ADU built through professional ADU construction remain in good condition?
Any ADU built to code with professional oversight is designed to last as long as the main residence — often several decades with routine maintenance. Durability depends to the quality of materials used, how consistently minor repairs are addressed, and if mechanical components are maintained on schedule. Brother & Brother Builders specifies high-quality components and follow all code requirements to deliver a structure that stands the test of time.
ADU Construction for San Jose Homeowners
Residential areas across San Jose present a wide range of property types that are ideally positioned for ADU construction. Residents in the Rose Garden district have found their lots work well for both attached and detached adu construction near San Jose projects. Communities around the Capitol Expressway corridor are seeing more homeowners add secondary units as multigenerational living becomes more common. Whether your property is near downtown San Jose, our team has likely worked nearby.
Local regulatory bodies in this area has developed specific protocols for ADU construction that our team navigates routinely. Location near major arterials like Story Road or Tully Road can affect how quickly permits are approved for a given ADU project. Our familiarity with this region's building landscape means smoother project delivery from kickoff through certificate of occupancy.
Start Your ADU Construction Planning Session Today
Should you be thinking about how to explore what an ADU could look like on your lot, Brother & Brother Builders is ready to guide you. Our experts offer licensed expertise in ADU construction for many different project types — from modest studio builds to fully independent secondary homes. Every project starts with a thorough and honest property review where we learn what you're trying to accomplish and provide an honest assessment of what's achievable.
Contact Brother & Brother Builders to set up your consultation. Even if you're just exploring the idea, we enjoy discuss timelines, costs, and design possibilities and help you take the next step. Building an ADU is a major decision — and we want to make sure it's the right one for you.
Brother & Brother Builders | 3109 Stevens Creek Boulevard | San Jose CA 95117 | (888) 412-2632