Convert Your Garage to an ADU in San Jose
Want to convert your garage to an ADU in San Jose? It is the fastest and most affordable way to add living space, with projects typically ranging from $125K to $225K. Custom Home handles design, permits, and construction with the same 3D visualization process we use for our custom homes.
How much does a garage conversion cost in San Jose?
Garage conversions in San Jose typically range from $125K to $225K depending on size, finishes, and plumbing requirements in 2026. Custom Home provides itemized pricing during Phase 1 so you know every cost before construction starts.
Garage Conversion Options in San Jose
A garage conversion transforms your existing garage into a fully permitted living space. In San Jose, conversions typically cost $125K-$225K, making them the most affordable way to add a bedroom, home office, rental unit, or guest suite to your property. Since the basic structure already exists, you save significantly compared to building new.
Custom Home handles everything from design through construction, using the same 3D visualization process that powers our custom homes. You see the finished space before any work begins.
What a San Jose Garage Conversion Includes
Every Custom Home garage conversion includes:
- Insulation and climate control for year-round comfort
- Electrical upgrades including lighting, outlets, and panel capacity
- Drywall, flooring, and interior finishes to your specifications
- Windows and natural light to meet building code requirements
- Plumbing for kitchen and/or bathroom (if included in scope)
- Separate entrance for independent access
San Jose Permits and Parking Requirements
San Jose’s Planning, Building and Code Enforcement department handles residential construction permits. The city offers online permit applications and plan check through the ePlan system. Standard custom home permits typically take 4-8 weeks for plan review. Pre-approved ADU plans can reduce permitting time to 2-3 weeks.
Under California state law, most cities cannot require replacement parking when you convert a garage to an ADU. This means you can move forward without building a new parking structure. Custom Home handles all permitting with San Jose’s building department.
Garage Conversion vs. Detached ADU in San Jose
Both options add living space to your San Jose property, but they differ in cost, timeline, and flexibility:
- Cost: Garage conversions ($125K-$225K) cost significantly less than detached ADUs because the structure already exists.
- Timeline: Conversions complete in 4-6 months vs. 8-12 months for detached units.
- Size: Conversions are limited by your existing garage footprint. Detached ADUs can be built up to 1,200 sqft.
- Rental value: Both can generate strong rental income, though larger detached ADUs typically command higher rents.
Custom Home can help you evaluate which option makes the most sense for your property and goals during our Phase 1 design process. For a full cost breakdown, read our garage conversion cost guide for the Bay Area.
Pricing for Garage Conversion in San Jose
Garage conversion costs in San Jose typically range from $125K to $225K depending on garage size, finish level, and plumbing requirements. This is significantly less than building a new structure since the foundation, framing, and roof already exist. Custom Home itemizes every cost during the design phase.
San Jose Permit Requirements
San Jose's Planning, Building and Code Enforcement department handles residential construction permits. The city offers online permit applications and plan check through the ePlan system. Standard custom home permits typically take 4-8 weeks for plan review. Pre-approved ADU plans can reduce permitting time to 2-3 weeks. Custom Home manages the garage conversion permit process, ensuring plans meet all local building codes.
Garage Conversion in San Jose: FAQ
What is the cost of a garage conversion in San Jose?
Garage conversions in San Jose typically cost $125K-$225K depending on garage condition, finish level, and plumbing scope. This is the most affordable way to add a permitted living space to your property.
How long does a garage conversion take in San Jose?
Garage conversions in San Jose typically take 4-6 months from design to completion, making them the fastest path to additional living space. The design phase runs 2-4 weeks, and construction takes 3-5 months.
Do I lose my parking if I convert my garage in San Jose?
Under California state law, most cities cannot require replacement parking for garage conversion ADUs. This means you can convert your garage without needing to build a new parking space, though on-street parking remains available.