How much does it cost to finish a basement?

Finishing a 1,000 sqft basement costs $32,000–$72,000 in 2026, or $32–$72/sqft. The biggest cost drivers are egress windows (often legally required for bedrooms, $2,500–$6,000 each), bathroom rough-in if not already present ($5,000–$15,000), and waterproofing if there's any moisture history ($3,000–$10,000). ROI on resale is 70–86% in cold-climate states where finished basements are baseline market expectation (MA, MN, IL, OH, PA, NJ). In Sun Belt states with shallow basements or none at all, the resale recovery is materially lower.