A French drain costs $10 to $35 per linear foot or $500 to $8,800 on average for a yard or curtain drain. An interior basement French drain costs $4,000 to $17,000.| HomeGuide
Crawl space insulation costs $1.00 to $4.50 per square foot or $500 to $3,700 on average. Spray foam insulation under a house costs $2 to $5 per square foot.| HomeGuide
Crawl space encapsulation costs $1,500 – $15,000. A vapor barrier costs $2 – $4 per square foot. Costs include a drainage system, insulation, repairs, and sealing.| HomeGuide