Junior ADU Conversion Cost across San Diego County
A junior ADU (JADU) garage conversion runs $50,000-$90,000 in San Diego County as a published market band. A JADU must sit within the single-family residence, so only an attached garage can follow that path. State law requires an exterior entrance. The unit may share sanitation with the house or have its own. A detached garage cannot be a JADU.
What moves the price
- Whether the JADU shares the main bathroom or gets its own half-bath
- Kitchenette scope (sink and counter only vs. full kitchenette with cooktop)
- Attached garage location relative to existing plumbing stacks
- Whether an interior connecting door to the main home is required or removed
What's included
- JADU permit submittal as required by the reviewing department
- Kitchenette plumbing and electrical
- Shared or added bathroom fixtures
- Insulation, drywall, and flooring for the 500 sq. ft. maximum footprint
- Interior or exterior entry modification per California JADU law
Common questions
Why is a JADU cheaper than a full ADU?
California JADU law caps the unit at 500 square feet. It can share sanitation with the house, which is a smaller plumbing scope than a full ADU kitchen and bath. It still needs an exterior entrance. A detached garage cannot be a JADU.
Do I need a contractor license to build my own JADU?
Owner-builder rules apply, but most homeowners hire a licensed crew for the plumbing, electrical, and structural work regardless. Garage Convert SD is a referral service that matches you with a licensed local crew for the build; verify any pro’s California contractor license at cslb.ca.gov.
Can I rent out a JADU?
A JADU can be rented for terms longer than 30 days where local rules allow. Occupancy can apply when the unit shares sanitation with the house, and generally does not when it has its own sanitation. The owner cannot sell the JADU separately. Confirm the current rule with the reviewing department.
Need a written jadu cost for your project?
Insured local crews across San Diego County put the scope in writing.