Full ADU Conversion Cost across San Diego County
A full ADU garage conversion in San Diego County runs $75,000-$150,000, covering permits, plans, and every trade needed to turn the garage into a self-contained unit with its own kitchen, bathroom, and entry. The spread depends mostly on garage size, whether a separate electrical meter is added, and how far new plumbing has to run from the existing house connection.
What moves the price
- Distance from the garage to the nearest sewer and water line
- Whether the ADU gets its own electrical meter or shares the main panel
- Finish grade on kitchen and bathroom fixtures, cabinets, and flooring
- Structural work needed to meet ADU ceiling height and egress rules
- Detached vs. attached garage (detached often needs a new utility trench)
What's included
- Architectural drawings and structural calculations
- City or county permit submittal and plan check
- Full kitchen and bathroom rough-in and finish
- New electrical circuits, subpanel, and HVAC
- Insulation, drywall, flooring, and exterior wall infill
- Final inspection and certificate of occupancy coordination
Common questions
What is the cheapest way to get a full ADU garage conversion?
The lowest-cost full ADU projects are attached garages already close to the main sewer and water lines, with a shared electrical panel instead of a new meter, and mid-grade fixtures. That combination keeps a project closer to the $75,000-$100,000 end of the range.
Does a full ADU conversion cost more than building a detached ADU from scratch?
No. Converting an existing garage is almost always cheaper than new detached construction because the foundation, framing, and roof already exist. New-build detached ADUs in San Diego County typically start well above the top of the garage-conversion range.
Is the full ADU cost the same across San Diego County?
The construction cost itself is fairly consistent countywide. What varies by jurisdiction is the permit timeline and, in some cases, plan check fees, which is covered on the local city page for each area.
Need a written full adu cost for your project?
Insured local crews across San Diego County put the scope in writing.