Radon Mitigation Cost Calculator

Radon mitigation costs $800–$4,000 for most homes, with the average system running $1,000–$2,500. Sub-slab depressurization (most common) costs $800–$2,500, drain tile suction $1,000–$3,000, sump pit suction $800–$2,000, and crawlspace membrane systems $1,500–$4,000. Larger or more complex homes cost more. Add $125–$400 for radon testing, $200–$600 for crack sealing, and $200–$400 for a high-suction fan upgrade.

The EPA recommends mitigation at radon levels of 4 pCi/L (picocuries per liter) or higher. Levels between 2–4 pCi/L should also be considered for mitigation. There is no safe level of radon — it is the second leading cause of lung cancer after smoking, causing about 21,000 US deaths annually. The EPA action level of 4 pCi/L represents a significant health risk — equivalent to smoking 8 cigarettes per day. Most mitigation systems reduce radon by 80–99%, typically below 2 pCi/L.

The most common method, sub-slab depressurization, works by creating negative pressure beneath the foundation slab to draw radon gas out before it enters the home. A pipe is inserted through the slab into the gravel layer below, and a continuously running fan pulls radon-laden air up through the pipe and vents it above the roofline. The system runs 24/7 using about $50–$100/year in electricity. For crawlspaces, a heavy-duty vapor barrier covers the ground with a similar suction system beneath.

Most radon mitigation systems are installed in 3–5 hours for a standard home. The process includes: drilling a 4–5 inch hole through the basement slab, installing a PVC pipe from below-slab to above-roof, mounting the radon fan in the attic or exterior, sealing the slab penetration and any visible cracks, and connecting electrical for the fan. Crawlspace systems take 4–8 hours due to vapor barrier installation. Post-installation radon testing should be done 24–48 hours after system activation.

Yes, radon testing ($125–$400 professionally, $15–$30 for DIY kits) should always be done before mitigation to confirm elevated levels and establish a baseline. Short-term tests (2–7 days) provide a quick screening. Long-term tests (90+ days) give a more accurate annual average. Post-mitigation testing is essential to verify the system reduced radon below 4 pCi/L. Test every 2 years after mitigation, or immediately if the system fan fails.

Yes, an installed radon mitigation system can be a selling point by addressing a common buyer concern. The $1,000–$2,500 investment prevents radon from becoming a deal-breaker during home inspections. Many home buyers require radon testing and will negotiate $2,000–$5,000 off the price if levels are high and no system exists. Having a functioning system with documented test results speeds up the sale process and demonstrates responsible homeownership.

Radon mitigation systems last 20+ years for the piping components and 5–10 years for the fan. The PVC piping, sealed slab penetrations, and crawlspace membranes are essentially permanent. The radon fan is the only moving part and will eventually need replacement ($200–$400 including installation). Signs of fan failure: no air flow at the exhaust pipe, system manometer reads zero, or increased radon levels. Most systems include a U-tube manometer that visually indicates the fan is working.

The EPA divides the US into three radon zones. Zone 1 (highest potential, >4 pCi/L average): Iowa, North Dakota, Minnesota, Pennsylvania, Ohio, Colorado, and parts of the Appalachian and Rocky Mountain regions. Zone 2 (moderate, 2–4 pCi/L): Most of the eastern US, Midwest, and Mountain West. Zone 3 (lowest, <2 pCi/L): Gulf Coast states, parts of the Southwest. However, elevated radon can occur in any state — 1 in 15 US homes has radon above 4 pCi/L regardless of zone.