Nobody else around here publishes radon pricing, so we will: the real ranges, what pushes a quote up or down, and how to judge a bid in a state that doesn't license this work.
Call (605) 600-8804Send your test result and foundation type — basement, slab, or crawl space — and we'll turn it into a firm price. Call (605) 600-8804 or use the form.
A standard single-suction sub-slab radon system in the Rapid City area typically costs about $1,200 to $2,500 installed. The South Dakota DANR pegs the statewide average installation near $1,200. Crawl spaces, multiple suction points, and large finished basements push the price higher; your firm number comes from a look at your foundation.
Last updated July 2026 · Ranges reflect typical residential installs in the Rapid City area.
Every house gets one of a few system designs, and the design is what sets the price. The ranges below are typical for the Rapid City area; the right-hand column tells you when each one applies.
| System type | Typical cost | When your house needs it |
|---|---|---|
| Single-suction sub-slab | About $1,200 – $2,500 installed | One pipe cored through the basement or slab floor, one fan, discharge above the eave. Fits most homes in the area. |
| Crawl-space sub-membrane | Above the standard range — quoted after inspection | A heavy liner sealed across the crawl-space floor with suction drawn from beneath it; more material and labor than a slab job. |
| Multi-suction or combination | Upper end of the range and beyond | Large footprints, additions on separate slabs, or tight soil that a single suction point can't depressurize. |
| Passive-to-active conversion | Typically less than a full new system | A builder-installed passive stack gets a fan and wiring so it actually pulls — common in newer construction. |
| Radon fan replacement | $145 – $300 for the fan, plus labor | The fan is the wearing part of any system; average life is about 11 years. The piping stays. |
| Post-mitigation verification test | Included with every install | Confirms the number actually dropped below 4.0 pCi/L before we close the job out. |
Most Rapid City homes — a basement, decent gravel under the slab, one suction point — land in the first row. The rest of the table exists because foundations differ, and a quote should reflect your house rather than a one-size menu.
The question a quote really answers is: how hard is it to depressurize the soil under this particular house? A handful of factors do most of the deciding:
Two same-year houses on the same street can quote differently because of what's under the concrete. That's why we price from your actual foundation — and why the number we give you holds.
Roughly $3 a month — that's the DANR's own operating figure for a radon fan in South Dakota, even though the fan runs around the clock. Continuous operation is the point: the fan keeps the soil under your home at lower pressure than your living space, and it does it for about what a light bulb draws. As safety equipment goes, it's among the cheapest a house can carry.
The long-term line item is the fan itself. Average lifespan runs about 11 years, and when one wears out the fix is a $145–$300 replacement fan plus the labor to swap it — not a new system. The pipe, the sealing, and the manometer all stay. If your fan has gone quiet or the U-tube gauge reads level, our repair and fan replacement service handles any brand, whoever installed it.
Here's something most homeowners don't know: South Dakota doesn't license radon contractors. No state exam, no required certification, no inspector signing off — anyone with a drill and a fan can call themselves a radon company tomorrow. That's not a scare line; it's the regulatory reality, and it explains why bids for the "same" job can look wildly different.
A low bid can be low because your house is simple — or because the bid quietly skips the steps that make a system work: no diagnostics before coring, an undersized fan, sump lids and slab cracks left unsealed, no follow-up test. A pipe on the wall that leaves your level above 4.0 pCi/L didn't save you money; it doubled your cost, because now someone has to fix the fix. Whoever you hire — including if it isn't us — get three answers in writing: Is the work built to the ANSI/AARST standards? What diagnostics happen before the price is set? And is a post-mitigation verification test included? The national certifying bodies, NRPP and NRSB, exist precisely because the state stays out of it — voluntary standards are the only floor this market has, so insist on them.
Tell us your test result and what's under your house, and you'll have a firm number to plan around today. No visit, no pressure.
(605) 600-8804The number we give you buys a finished, verified system — not an entry price that grows on install day. Every standard job covers:
Installation is normally a single visit of three to five hours, and you don't have to leave the house. Haven't tested yet? Start with radon testing — South Dakota even offers free kits. And if the high number showed up mid-transaction, our radon and real estate page covers pre-closing timelines and who usually pays.
In the Rapid City area, a standard single-suction sub-slab system typically runs about $1,200 to $2,500 installed, and the South Dakota DANR puts the statewide average installation near $1,200. Crawl-space, multi-suction, and large finished-basement homes come in higher. The only way to get your exact number is a written quote based on your foundation.
Partly because homes vary — and partly because contractors do. South Dakota doesn't license radon work, so there's no floor under quality: one bid may include diagnostics, sealing, and a verification test while another is a fan on a pipe. Compare what's in the bid, not just the number at the bottom, and insist on ANSI/AARST-standard work with a follow-up test in writing.
About $3 a month in electricity, per South Dakota DANR figures — the fan draws roughly what a light bulb does even though it runs 24/7. Fans last about 11 years on average, and a replacement runs $145 to $300 for the fan, plus the labor to swap it.
Generally no. Policies treat a radon system as a home improvement rather than sudden, accidental damage, so it isn't a typical claim. In a home sale, though, the cost is often negotiated between buyer and seller — see our radon and real estate page for how that usually plays out.
Usually, yes. A crawl space can't be depressurized like a slab, so we lay and seal a heavy membrane across the floor and draw suction from beneath it — sub-membrane depressurization. The extra material and labor put it above the standard sub-slab range. We quote it firm after seeing the crawl space.
The piping is effectively permanent; the fan is the wearing part, with an average life of about 11 years. When a fan quits, the fix is a $145–$300 replacement fan plus labor — not a new system. A glance at the U-tube manometer on the pipe tells you at any moment whether the system is pulling.