Constructionfrench-drain, drainage
How Much Does a French Drain Cost in 2026? (Interior & Exterior Pricing)
How Much Does a French Drain Cost in 2026? French drains cost $10 to $100 per linear foot installed in 2026, with exterior yard drains running $10-$35/ft and interior basement systems running $40-$100/ft. The average residential project falls between $2,000 and $10,000, while full interior basement perimeter systems can reach $4,000-$17,000. The wide price range comes down to one question: are you digging through your yard or cutting through your basement floor? Seven French drain systems installed across eastern Pennsylvania show a pricing gap between exterior and interior work that surprises most homeowners. A 120-foot exterior French drain completed in Lehigh County came to $3,360 -- about $28 per linear foot. A 90-foot interior basement French drain in Allentown came to $7,200 -- $80 per linear foot. Same type of pipe, same gravel, same basic concept. The difference was cutting and removing a concrete floor, working in a confined space,...