Additions and Conversions
ADUs and Conversions: costs by job
Install, replace, repair and maintain costs for every adus and conversions job we track, with the trade required and how DIY-friendly each one is.
Model reviewed August 2026
Cost comparison
Typical national figures for a standard single-family home.
| ADU InstallationTypical $180,000 · General contractor · DIY 1/5 | $90,000 – $350,000 |
|---|---|
| Garage ConversionTypical $38,000 · General contractor · DIY 1/5 | $15,000 – $80,000 |
| Basement FinishingTypical $45,000 · General contractor · DIY 1/5 | $20,000 – $95,000 |
| Attic ConversionTypical $50,000 · General contractor · DIY 1/5 | $22,000 – $110,000 |
ADU
Variants: Detached · Attached · Garage conversion · Basement