Conversion Paths
Three ways to convert
- Garage conversions — the classic: insulated envelope, new windows and entry, full kitchen and bath. Typically $80,000–$180,000.
- Basement ADUs — legal egress, moisture control, separate entry. Often the largest converted space.
- Attached additions — a bump-out or over-garage suite with its own entrance.
Cost: conversions run $150–$300/sq ft in 2026 — roughly half the cost of a detached cottage per square foot. Timeline: 4–7 months including permits.
Numbers for your project: cost calculator →
What Makes It Legal
Code items we solve for you
01Egress & light
Code-compliant windows and exits — the make-or-break item in basements and garages.
02Fire separation
Rated assemblies between units, interconnected alarms.
03Systems
Heating, hot water, electrical capacity — right-sized for independent living.
04Permits
Full permit set and inspections — a legal ADU appraises and rents; an illegal one is a liability.
Have a garage or basement?