This is part of our Garage ADU series for San Antonio homeowners. Also in this series: cost · rules & permits · rental income · financing · timeline · FAQs.
Searches for “ADU garage” rank among the top ADU-related searches in the country — and cost is the number-one question behind them. Here’s the honest breakdown for San Antonio homeowners.
Garage Conversion Cost Ranges
Because the walls, roof, and foundation already exist, a garage conversion is consistently the most affordable way to build an ADU — often half the cost of a detached new build. Nationally, projects fall into these bands:
- Basic living space (insulation, drywall, flooring, electrical — no plumbing): $15,000–$30,000. Good for a home office, gym, or studio.
- Full ADU without a bathroom (adds a kitchenette): $20,000–$35,000.
- Full ADU with kitchen and bath: $35,000–$60,000+.
In high-cost coastal markets, full garage ADU conversions run $150,000–$230,000 all-in. Texas and San Antonio land well below that, but your number depends on the variables below.
What Moves Your Price Up or Down
- Plumbing routing — how far the new bathroom and kitchen sit from existing water and sewer lines
- Electrical panel capacity — older panels often need an upgrade
- Structural condition — foundation, framing, and roof health
- Finishes — rental-grade vs. high-end kitchens and baths
- Permits and fees — plan review and city fees vary by scope
The Only Way to Get Your Number
Ranges are a starting point, not a quote. Every garage is different, and a walkthrough is the only way to price yours accurately — which is exactly what our free estimate includes.
Is Your Garage a Candidate?
If your garage is structurally sound, your lot meets setback requirements, and your HOA allows it, you’re likely a strong candidate. The fastest way to find out is a free feasibility review — we’ll tell you straight whether the numbers and the rules work for your property.
Book a free estimate or start with our Casita / ADU Cost Guide for San Antonio & the Hill Country.