Unlock New Space with Quality ADU Construction
Property owners throughout San Jose, CA are realizing that adding an accessory dwelling unit is one of the most practical investments they can make. ADU construction creates a powerful new living space on your existing property — whether you want to create a private workspace. Brother & Brother Builders has guided hundreds of local homeowners see these visions to life with skill and integrity.
The interest in ADU construction has grown rapidly in recent years, and it's no mystery. California state law has streamlined permitting for homeowners to construct these secondary units, and local municipalities like San Jose have encouraged the trend as a way to increase density responsibly. If you're planning 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 project. Our team knows the San Jose building codes, the engineering requirements, and the aesthetic decisions that make an ADU truly livable. Should you want to learn about what ADU construction could mean for your property, this guide explains 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 self-contained living space — including a kitchen, bathroom, sleeping area, and its own entrance — that sits on the same property as a primary residence. ADU construction can take several forms, including detached backyard units, attached additions, garage conversions, and even interior space reconfigurations.
Mechanically, the process begins with a comprehensive review of your lot, where our professionals evaluate property boundaries, available square footage, and infrastructure capacity. From there, architectural drawings 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, HVAC, drywall, flooring, and exterior finishes. The result is a completely finished living unit attached to or separate from your main home.
What separates excellent ADU construction from an average project 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 designed to handle full-time occupancy. Brother & Brother Builders treats each project with the same professional rigor we use on major custom home projects.
Key Reasons to Choose ADU Construction
- Increased Property Value — ADU construction contributes significant market value to your property, often increasing appraised value substantially when it's time to sell.
- Revenue Generation — A completed ADU can be rented as a long-term rental or short-term vacation unit, creating ongoing passive income for the homeowner.
- Multi-Generational Living — ADU construction provides adult children a comfortable home of their own without losing proximity to the family.
- Personalized Layouts — From two-bedroom configurations, ADU construction can be tailored to the intended occupant's lifestyle.
- Streamlined Approval Process — Recent state legislation has cut down the red tape associated with ADU construction, making the process that is faster and more affordable than ever before.
- Responsible Property Development — Building an ADU works within your current footprint instead of consuming open land, which supports broader sustainability goals.
- Independent Living Areas — Unlike a bedroom addition, ADU construction creates a truly separate unit where tenants live autonomously.
- Durable Return on Investment — A well-built ADU holds its value for decades, providing both livable square footage and monetary benefit.
The ADU Construction Procedure Step by Step
- Initial Property Assessment and Feasibility Review — Our builders assess your property to evaluate setbacks, lot coverage limits, and utility connections. This stage clarifies exactly what ADU types will work before any money is spent on design.
- Blueprint Development and Layout Design — Our design team create precise architectural drawings tailored to your needs. Layouts are carefully considered to create practical, comfortable living.
- Permit Submission and Municipal Review — ADU construction in San Jose demands documentation to the city's building department for inspection and clearance. Brother & Brother Builders coordinates the permitting on your behalf, resolving any revision requests promptly.
- Site Preparation and Foundation Work — Once permits are issued, physical construction begins. This includes grading the site, completing foundation work, and establishing utility connections.
- Shell Construction and Exterior Finishing — The structural frame is erected 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 heating, cooling, drainage, and power infrastructure that make the ADU ready for occupancy. Every system is reviewed at each code checkpoint throughout ADU construction.
- Interior Finishing and Final Inspections — Countertops, hardware, finishes, and fixtures are installed and finished to the approved plan. A closing municipal review grants legal occupancy status and the unit is officially approved for use.
Who Is a Right Fit for ADU Construction?
People who see the greatest return from ADU construction generally fit within a few recognizable groups. If you have a residential property with enough lot space to meet setback requirements, you're already well-positioned. Homeowners wanting to add a revenue stream 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 detached creative or business space that remains away from your family's daily life. Property investors and rental owners who already own residential properties are also well suited for ADU construction, since the return on investment is well-documented.
Those who should discuss alternatives first include sites with unusual get more info utility access challenges. Parcels in historic districts or HOA-restricted communities may need a modified approach. Brother & Brother Builders reviews each property case by case to recommend the right path forward.
ADU Construction Frequently Asked Questions
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. Permitting alone can take two to four months in San Jose, so beginning the process sooner rather than later is wise. Simpler garage conversions can move faster, while larger new construction ADUs require more time.
What does ADU construction typically cost?
Pricing depends on many factors based on whether it's a conversion or new construction. In the San Jose area, ADU construction generally falls between $150,000 to $400,000 or more for a detached new build. Interior conversion projects are generally priced lower, sometimes in the $80,000 to $150,000 range. A precise cost projection can only be developed after a full site assessment.
Is ADU construction intrusive while it's underway?
The level of disruption depends on where the ADU is being built. Standalone ADU projects are typically less disruptive, since work happens away from the main house. Interior conversions may require temporary access during certain phases of construction. Our team communicates clearly about upcoming work and timelines.
Do I need to leave my home during ADU construction?
Generally speaking, you are not required to vacate your primary residence during ADU construction. The vast majority of projects are designed so that you remain on the property throughout the construction timeline. Exceptions may arise if significant structural connections require temporary shutoffs in ways that require short-term access disruption. The team at Brother & Brother Builders will discuss these scenarios during the kickoff meeting.
How long will an ADU built through professional ADU construction last?
An ADU constructed with quality materials can be expected to last as long as the main residence — indefinitely with proper upkeep. Longevity is tied to the systems installed, how consistently minor repairs are addressed, and whether systems like roofing and plumbing are serviced regularly. Brother & Brother Builders specifies high-quality components and comply with all local building codes to deliver a structure that stands the test of time.
ADU Construction for Local Homeowners
Residential areas across San Jose present a variety of property types that are well suited for ADU construction. Homeowners in the Willow Glen neighborhood frequently see their parcels are well configured for ADU builds. The Berryessa area have seen growing ADU activity as housing demand rises. Whether your property is near downtown San Jose, our team has likely worked nearby.
San Jose's permitting office follows defined procedures for ADU construction that experienced builders know well. 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 these local conditions means more accurate timelines and budgets from the first meeting to the final inspection.
Start Your ADU Construction Consultation Today
If you're ready to add an ADU to your property, Brother & Brother Builders is the team to call. We bring proven skills in ADU construction across a wide range of project types — from simple garage conversions to fully independent secondary homes. The process begins with a thorough and honest property review where we understand your vision and provide an honest assessment of what the project will involve.
Get in touch with our office to schedule a site visit. No matter where you are in the decision-making process, we're glad to walk through your options, review completed projects and make sure you feel confident before committing. ADU construction is a significant investment — 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