What a Radon System Costs in Joliet & Will County (2026)
Straight to the numbers. In and around Joliet — Shorewood, Crest Hill, Lockport, and Plainfield included — a professionally installed radon mitigation system typically costs $1,200 to $1,700. The easy cases come in near $800; the complicated ones run $2,000 to $3,000. Chicago-area cost surveys put the metro average around $1,300, which squares with what Will County homeowners actually pay. Below: what sorts a house into each band, and the two nearly-free steps that come first.
Step zero costs $8
Before pricing a fix, prove you need one. The Will County Health Department sells passive test kits for $8 — prepaid lab postage and a written report included — at its Joliet, Bolingbrook, and Monee offices. If the kit comes back at or above 4.0 pCi/L (the EPA action level), confirm with a second test or a licensed 48-hour measurement, then talk installs. Skipping the retest and buying a system off one screening result is the most common way homeowners overspend on radon.
Step one-half: check for the pipe you may already own
Illinois has required passive radon-resistant construction in new homes since June 1, 2013. If your house is newer than that — common in Plainfield, where the median home dates to 2003 and construction ran well past it — look for the capped PVC riser coming off the slab. Activating an existing passive pipe with a fan is the budget end of mitigation: you're buying a fan, a wiring run, and a licensed contractor's activation rather than concrete coring and full pipe routing. Illinois law does require an IEMA-licensed mitigation pro to do it.
What sorts everyone else into a price band
The $800–$1,200 band: one accessible foundation, decent gravel under the slab, exterior pipe route, unfinished basement or utility area. Lots of 80s–2000s subdivision homes across Joliet's west side, Shorewood, and Lockport's newer sections live here. The median Joliet home was built in 1985 — squarely this profile.
The $1,200–$1,700 band — most houses: add any one wrinkle. A sump pit that needs a sealed lid and becomes the suction point. A finished basement forcing an interior chase to the attic. Tighter sub-slab material needing a larger fan. A second slab under an addition. Permit fees vary a bit by town — Joliet's Building & Inspectional Services, Plainfield's Building & Code Enforcement, and the Shorewood, Crest Hill, and Lockport building departments all treat this as routine mechanical work, folded into the quote.
The $2,000–$3,000 band: multiple foundation types under one roof, big footprints needing two suction points, or a dirt/gravel crawl space that needs a sealed membrane system. Joliet's historic-district housing — limestone foundations, stone cellars, basement-plus- crawl layouts — books into this band most often, as do large newer homes on combination foundations.
Operating cost and lifespan
Budget a few dollars a month in electricity for the fan, which runs continuously and lasts 10–15 years; replacements are a modest service call, not a re-install. The pipe and seals are effectively permanent. Every licensed install finishes with the state-required license tag and a verification test, so you (and any future buyer, under Illinois's 2008 seller-disclosure law) have paper proving the number came down.
Watch-outs
Two flags worth walking away from: anyone quoting without asking about your foundation, and anyone who can't produce an IEMA license number — Illinois has licensed this trade since 1997, and the license lookup is public. A suspiciously cheap bid that skips sealing, skips the permit, or vents below the eaves isn't a bargain; it's a system that moves the gas around instead of out.
Want the number for your specific house? The quote form takes a minute; answers come back same-day with a firm price from a licensed installer.