Basement finishing often consists of lighting, built-in shelves, waterproofing, framing, plumbing, wiring, drywall, flooring, an HVAC system, and egress windows, transforming unfinished basement space into useable living space. Basement finishing cost breakdown When putting up a basement finishing estimate, the family room or living room (between 204 – 480 square feet) will be the most expensive, costing between $10,000 and $20,000. The bathroom (45 – 72 square feet) is located on the lower end. The closer you go to high-end materials, such as hardwood flooring, copper piping, or imported marble, the greater the cost. A 600-square-foot basement finish costs between $23,960 and $28,240 with average-quality materials. Basement Finishing Cost per Square Foot The typical cost to finish a basement is $32 to $47 per square foot or around $39 per square foot. A 500-square-foot open-plan basement will cost roughly $20,000 to finish, while a 1,500-square-foot basement with three rooms and a bat...