Garage conversions are the single most popular ADU type we build. They're the fastest, most affordable way to add a legal rental unit to your property — and California law has made them easier to permit than ever before.
But they're not right for every property. Here's how to know if yours qualifies and what to expect if it does.
Does Your Garage Qualify?
Garage Conversion Checklist
- Attached or detached garage on a residential lot
- Ceiling height of at least 8 feet (or 7'6" with conditions)
- Minimum floor area of 150 square feet
- Ability to add a bathroom and kitchen (plumbing access)
- No required replacement parking (most cities now waive this)
- Setbacks already met by existing structure
If your garage checks most of these boxes, you're likely a strong candidate. We can confirm eligibility in a free 30-minute site visit.
What's Included in a Garage Conversion
- Insulation of walls, ceiling, and slab (for thermal and sound)
- New flooring (concrete prep, subfloor, finished floor)
- Full kitchen installation — cabinets, counters, appliances, sink
- Bathroom addition — toilet, shower or tub, vanity
- Electrical panel upgrade and new circuits
- HVAC — mini-split system for heating and cooling
- Windows and exterior door upgrades
- Drywall, paint, and interior finishes
- Garage door replaced with wall, window, or French doors
Garage Conversion Costs in 2026
$135,000 – $175,000All-in garage conversion cost in Santa Cruz County, including permits, design, and construction
The range depends on size, existing condition of the garage, complexity of the plumbing run, and finish level. A basic 400 sq ft single-car garage conversion will come in lower. A 600 sq ft two-car garage with high-end finishes will push the upper range.
Pros of Garage Conversion
- Lowest cost ADU option — Foundation and structure already exist
- Fastest to permit — Existing footprint, no new structure
- No setback issues — Garage is already where it is
- Immediate rental income — 6–9 month timeline from start to rent
- Significant property value increase — Typically adds $150,000–$200,000 in appraised value
Cons of Garage Conversion
- Loss of garage storage — You'll need to plan for parking and storage elsewhere
- Size limitations — Most garages are 400–600 sq ft, limiting to studio or 1BR
- Existing condition matters — Old wiring or plumbing can add cost
- Ceiling height — Low garages may not meet minimum requirements
💡 Pro Tip: We've completed dozens of garage conversions in Watsonville and Santa Cruz. The most common surprise is the cost of upgrading the electrical panel — older homes often need a panel upgrade to support the new unit. We always check this upfront so there are no surprises mid-project.
Real Numbers: Garage Conversion ROI
A 1-bedroom garage conversion ADU in Watsonville currently rents for $1,800–$2,400/month. At $2,000/month, a $150,000 conversion pays for itself in just over 6 years — then generates $24,000 per year in pure income indefinitely. That's a better return than most investments.