Accessory Dwelling Units
San Jose ADU Builders & Contractors
Maximize Your Property's Potential
An Accessory Dwelling Unit (ADU) is one of the smartest investments you can make as a Bay Area homeowner. Whether you want rental income, a space for aging parents, or a private home office, an ADU adds value and versatility to your property.
California’s relaxed ADU regulations have made it easier than ever to build. QA Builders navigates the entire process from design and permits to construction and finishing so you can start enjoying your new space sooner.
We’ve completed dozens of ADU projects across San Jose and the Bay Area, from garage conversions to ground-up custom builds.
Why Build an ADU?
Rental Income
A well-designed ADU in San Jose can generate $2,000-$4,000+ per month in rental income, often covering your mortgage.
Multi-Generational Living
Provide independent living space for parents or adult children while keeping family close.
Property Value Boost
ADUs can increase your property value by 20-30%, making them one of the best ROI home improvements.
Flexible Use
Home office, art studio, guest house, or Airbnb an ADU adapts to your changing needs over time.
ADU Types & Services
We build every type of ADU permitted in San Jose, from simple conversions to custom detached units, all designed to maximize your space and investment.
Detached ADUs
Standalone structures built from the ground up with full kitchens, bathrooms, and living areas.
Attached ADUs
Extensions to your existing home with separate entrances and self-contained living spaces.
Garage Conversions (JADU)
Transform your existing garage into a livable unit one of the most cost-effective ADU options.
Two-Story ADUs
Maximize a small footprint with a two-story design that provides ample living space.
Design & Architecture
Custom designs that complement your main home's style and maximize the available space on your lot.
Permit & Zoning Navigation
We handle all permitting, zoning requirements, and city interactions from start to finish.
Our ADU Construction Process
Site Assessment
We evaluate your property, review zoning regulations, and determine the best ADU type and placement for your lot.
Custom Design
Our architects create plans that maximize space, complement your main home, and meet all code requirements.
Permitting
We handle all permit applications, plan checks, and utility coordination with the city of San Jose.
Foundation & Construction
Expert construction from foundation to roofline, with quality materials and skilled craftsmanship.
Interior Finishing
Full kitchen, bathroom, flooring, lighting, and all finishes installed to rental-ready or personal-use standards.
Inspection & Handover
Final city inspection, certificate of occupancy, and a thorough walk-through before we hand you the keys.
Why Choose QA Builders for Your ADU?
ADU construction requires specialized knowledge of California’s unique regulations, local zoning codes, and utility requirements. QA Builders has built dozens of ADUs and knows exactly how to navigate the process efficiently.
We handle everything in-house design, permits, construction, and finishing so you have one point of contact and one team accountable for your project’s success.
Our ADUs are built with the same quality and attention to detail as our full home remodels, ensuring your investment looks great and lasts for decades.
What's Included
- Full design services
- Permit & zoning compliance
- Foundation to finish construction
- Kitchen & bathroom installation
- Utility connections
- Landscaping integration
- Rental-ready finishes
- Energy-efficient design
Frequently Asked Questions
How much does an ADU cost to build in San Jose?
ADU costs typically range from $150,000 to $350,000+ depending on size, type, and finishes. Garage conversions are generally the most affordable option.
How long does it take to build an ADU?
From permits to completion, most ADUs take 6-12 months. Garage conversions can be faster (4-6 months), while custom detached units may take up to a year.
Do I need a permit to build an ADU in San Jose?
Yes, ADUs require building permits. However, California law has streamlined the process significantly. We handle all permitting for you.
Can I rent out my ADU?
Yes! San Jose allows ADU rentals. A well-designed ADU can generate significant monthly rental income, often $2,000-$4,000+ in the Bay Area.
Ready to Get Started?
Contact us today for a free consultation and detailed estimate for your adu construction project.