Radon Mitigation Cost in Wisconsin (2026)

Wisconsin Radon at a Glance

Wisconsin averages 4.8 pCi/L statewide — just above the EPA action level. The Wisconsin Department of Health Services estimates approximately 30–35% of Wisconsin homes test above 4 pCi/L.

The highest concentrations occur in southwest Wisconsin's Driftless Area — counties like Grant, Iowa, Lafayette, and Green that sit on lead-zinc mining geology and fractured dolomite. This region is geologically distinct from the glaciated rest of the state and runs significantly higher.

What Mitigation Costs in Wisconsin

Slab or Basement: $850–$1,900

• Standard slab, Madison metro: $900–$1,500
• Finished basement: $1,100–$1,800
• Milwaukee suburbs: $950–$1,700
• Southwest Wisconsin (often higher-suction required): $1,100–$2,000

Crawl Space: $2,500–$5,500

• Basic crawl space: $2,500–$3,500
• With vapor barrier: $3,000–$4,800
• Driftless Area, difficult terrain: $3,500–$5,500

Southwest Wisconsin: Plan for Higher Costs

Grant and Iowa counties in particular often require higher-suction fans and multiple suction points due to fractured bedrock sub-slab conditions. If you're in the Platteville, Lancaster, or Mineral Point area, budget at the higher end and get at least 3 quotes.

Wisconsin Resources

• Wisconsin DHS Radon Program: dhs.wisconsin.gov/radon or 608-261-6876
• Wisconsin-specific radon map: dhs.wisconsin.gov
• Verify NRPP: radonproficiency.org

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