Adu Construction
Brother & Brother Builders
Among the many building services offered by Brother & Brother Builders, accessory dwelling unit construction represents one of the most practical ways homeowners across San Jose and the wider Santa Clara County region can expand their living space. As a full-service general contractor based at 3109 Stevens Creek Blvd Ste A in San Jose, the company applies its construction and remodeling experience to ADU projects that add functional square footage to existing residential properties. This page profiles that specific corner of their work, how it fits into their broader capabilities, and the communities where it is delivered.
How ADU Construction Fits Into the Brother & Brother Builders Portfolio
An accessory dwelling unit is a self-contained secondary living space built on the same lot as a primary home. For Brother & Brother Builders, ADU construction sits naturally alongside their other structural offerings such as new home construction, custom homes, second story additions, garage conversions, and room additions. Because the company operates as a general contractor rather than a single-trade specialist, an ADU project can draw on the full range of services they already provide, from architectural services and design-build coordination to floor plan development, flooring installation, kitchen remodeling, and bathroom remodeling. That breadth allows the finished unit to function as a complete, livable home rather than a bare shell.
ADUs take several forms, and the right approach depends on the property, the homeowner's goals, and the existing structure. The table below outlines common paths that fall within the company's building and remodeling scope.
| Approach | What It Involves | Typical Considerations |
|---|---|---|
| Detached new-build ADU | A standalone unit constructed as fresh new home construction on the lot | Lot space, utility connections, and overall design-build coordination |
| Garage conversion | Transforming an existing garage into finished living space | Insulation, flooring installation, and kitchen or bathroom additions |
| Addition-based ADU | Expanding the footprint through room additions or a second story addition | Structural tie-in to the existing home and matching modern home design |
| Interior remodel to unit | Reworking existing interior areas into an independent dwelling | Drywall repair, interior painting, and separate kitchen and bath layouts |
What the Work Involves in Plain Language
Building an ADU is essentially building a small, complete home, and Brother & Brother Builders treats it that way. The process typically weaves together several of the trades the company already handles in-house or coordinates as the general contractor, including architectural services, design-build planning, custom cabinetry, countertop replacement, tile work, and finish painting. The goal is a unit that lives comfortably on its own, whether it is intended for extended family, a home office, or additional living quarters. Because the same team can guide a project from floor plan development through final finishes, homeowners deal with a single contractor across the arc of the build.
- Initial planning: Discussing the property, goals for the unit, and which ADU approach fits the lot and existing structure.
- Design and layout: Using architectural services, 3D home design tools, and floor plan development to shape the space.
- Design-build coordination: Aligning structural work, utilities, and finishes under one general contractor.
- Construction: Framing and building the unit, whether a new detached structure, conversion, or addition.
- Interior systems and finishes: Installing kitchens, bathrooms, flooring, cabinets, and countertops.
- Final detailing: Drywall repair, interior painting, and finishing touches to complete a move-in-ready space.
Serving San Jose and Santa Clara County Neighborhoods
Positioned along Stevens Creek Boulevard, a major commercial corridor linking San Jose with Santa Clara and Cupertino, Brother & Brother Builders is centrally located to reach ADU projects throughout the county. The company serves a wide span of communities, including Central San Jose, North San Jose, Willow Glen neighborhoods such as North Willow Glen, and areas like Winchester, Winchester Lynnhaven, Hamann Park, College Park, Fruitdale, Blackford, Cadillac West, and Rancho Rinconada. Their reach extends to neighboring cities such as Campbell, Cupertino, Sunnyvale, Saratoga, Los Gatos, Monte Sereno, and the Rivermark area of Santa Clara, along with districts like Japantown and Luna Park, Communications Hill, Delmas Park, and the Golden Triangle.
This is a part of Silicon Valley defined by established residential neighborhoods and landmarks familiar to residents countywide, from Westfield Valley Fair and Santana Row near the company's own location to the Winchester Mystery House, the Municipal Rose Garden, and Westgate Center. Farther afield, the areas they serve stretch toward attractions such as the Pruneyard, Vasona Lake County Park in the Los Gatos direction, and Emma Prusch Farm Park to the east. Building ADUs across such varied neighborhoods means adapting each unit to the character of the surrounding homes and the specifics of each lot.
What Distinguishes the Brother & Brother Builders Approach
What sets the company's ADU work apart is the range of building disciplines kept under one roof. Homeowners considering an accessory dwelling do not need to assemble separate designers, framers, and finish crews; Brother & Brother Builders combines architectural services, modern home design, green building options, smart home upgrades, and complete interior finishing within its general contracting practice. That integrated approach, paired with a central San Jose base and service across Santa Clara County, allows the company to treat each ADU as a full home-building project from concept through completion. Homeowners can reach Brother & Brother Builders by phone at +1 888-412-2632 to learn more about how this work applies to their property.
Getting here
From Casino M8trix
Casino M8trix sits about 5.7 miles out, or around 11 minutes by car. The route runs along Matrix Blvd to US-101 S, then over to I-880 S toward Brother & Brother Builders.
Common questions
What is the average cost to build an ADU in California?
ADU costs in California vary widely by size, finishes, and site conditions, but many detached units fall roughly between $150,000 and $400,000 or more, factoring in design, permits, utilities, and construction. Local factors like foundation work and access can shift totals significantly. Brother & Brother Builders, a general contractor on Stevens Creek Boulevard in San Jose, handles ADU construction across Santa Clara County and can scope projects to a homeowner's specific lot and budget.
Is there a $40,000 ADU grant available in California?
California previously offered the CalHFA ADU Grant Program, providing up to $40,000 toward pre-development and closing costs like design, permits, and impact fees. Funding rounds have opened and closed depending on state budgets, so availability changes over time. Homeowners in San Jose and greater Santa Clara County should verify current status through CalHFA. A general contractor like Brother & Brother Builders can help coordinate the construction side once financing is arranged.
What are the common mistakes when building an ADU in San Jose, CA?
Common ADU mistakes include underestimating utility connection costs, skipping proper permitting, poor space planning, ignoring setback and zoning rules, and choosing finishes that don't match long-term goals. Overlooking site drainage and access also causes delays. Working with an experienced general contractor helps avoid these pitfalls. Brother & Brother Builders, based in San Jose's 95117 area, offers design-build and floor plan development services that address planning and permitting early for Santa Clara County homeowners.
What are the disadvantages of ADUs in CA 95117?
ADUs can bring reduced yard space, upfront construction costs, potential property tax increases on the new structure, added maintenance, and the responsibilities of being a landlord if rented. Construction disruption during the build is another factor. Despite these, many San Jose homeowners find the added living space valuable. Brother & Brother Builders, a Santa Clara County general contractor, can walk property owners through practical trade-offs before committing to an ADU project.
What is the most expensive part of building an ADU in CA 95117?
The most expensive parts of an ADU are typically the foundation, framing, and utility connections—plumbing, electrical, and sewer tie-ins—along with kitchen and bathroom systems. Site preparation and permits also add up quickly. Costs rise when access is limited or existing infrastructure is far away. Brother & Brother Builders, serving San Jose and surrounding communities like Santa Clara and Cupertino, can assess a site to identify where the biggest expenses will land.
Does adding an ADU increase property taxes in California?
Building an ADU in California generally triggers a reassessment of only the new addition, not your entire property, so existing value keeps its established base under Proposition 13. The added structure is assessed at its market value and taxed accordingly. Rules can vary, so consult the Santa Clara County Assessor. Brother & Brother Builders, a San Jose general contractor, focuses on the construction while homeowners confirm tax details with local authorities.
What does a 500 sq ft ADU look like in CA 95117?
A 500-square-foot ADU typically fits a compact one-bedroom or open studio layout, with a full kitchen, bathroom, living area, and often a small sleeping space. Smart layouts and modern design maximize the footprint. Brother & Brother Builders offers 3D home design tools, floor plan development, and design-build services from its Stevens Creek Boulevard location, helping San Jose and Santa Clara County homeowners visualize how a 500 sq ft unit fits their property.