Radon mitigation in New Hampshire runs $900 to $6,000, and most homes land around $1,950 to $2,250. A simple single-point system on an open basement sits at the low end. A big house, a finished basement, a crawl space, or a very high radon reading pushes it up. Radon testing is a separate, cheap step — about $50 — and you do it first, because you cannot price a fix until you know your number.
Radon mitigation cost at a glance (603, NH range)
| What you have | Typical position in the range |
|---|---|
| Single suction point, open unfinished basement | Low end, near $900 |
| Standard home, one or two suction points | Most jobs, about $1,950 to $2,250 |
| Large home, multiple suction points, or very high radon | Upper end |
| Finished basement (pipe to hide, finishes to restore) or crawl space | Upper end, toward $6,000 |
The 603 NH range for radon mitigation is $900 to $6,000. The only way to get your real number is an on-site look, but the factors below tell you where your job lands.
How much does radon mitigation cost in NH?
In New Hampshire, a radon mitigation system from 603 falls in the range of $900 to $6,000, with most homes landing around $1,950 to $2,250. The low end is a single-point system venting one open, unfinished basement. The high end is a large or finished home, a crawl space, or a reading high enough to need more than one suction point and a bigger fan.
Testing is its own thing, and it is cheap. A professional radon test from 603 is $50, separate from any mitigation. You always test before you mitigate, because the level on the report decides how the system gets designed.
We do not quote a flat price over the phone. Every house is different, and the honest answer to “what will mine cost” is a free on-site look. The sections below show you exactly what moves the number.
What you pay by system type
The kind of system your home needs is the biggest driver of where you land in the $900 to $6,000 range. Here is how the common types compare.
Single-point sub-slab suction (most common, low end)
Most homes with a concrete basement floor get this. We core one hole through the slab, run a sealed PVC pipe up and out through the roofline, and add an inline fan that pulls radon gas out from under the slab before it reaches your living space. One suction point, one fan, one run of pipe. This is the simplest system and it sits at the low end of the range.
Multiple suction points (mid to upper)
Bigger footprints, additions, or a slab broken up by interior footings sometimes need two or more suction points tied into one fan, or a stronger fan, to pull radon evenly from under the whole floor. More pipe, more labor, and a larger fan move the price up from the single-point base.
Crawl-space membrane systems
A dirt or fieldstone crawl space cannot be vented through a slab, because there is no slab. Instead we seal the floor with a heavy membrane and pull the radon out from beneath it (sub-membrane depressurization). Older New England homes — the fieldstone foundations and half-basement, half-crawl layouts we work on every week — often need this. It is more involved than a clean slab job, so it sits in the upper part of the range.
What moves the price within $900 to $6,000
Two homes a mile apart can get very different quotes. Here is what actually moves your number.
Foundation type. A flat, open concrete slab is the easy case. A fieldstone or rubble foundation, common in older NH homes, has gaps and an uneven floor that make sealing and suction harder. A crawl space needs a membrane system instead of a slab core. The harder the foundation is to seal, the more the job costs.
Home size and slab area. A bigger floor means more pipe to route and often a stronger fan to pull radon across the whole slab. Square footage moves the price.
Number of suction points. One hole through the slab is the base case. A second or third suction point adds labor and materials, and it is usually the high radon reading or a chopped-up floor plan that calls for it.
Fan size and a radon monitor. A higher starting level needs a more powerful fan to get you under the action level and keep you there. A continuous radon monitor, which shows your level in real time, can be part of the build.
Routing through a finished basement. Hiding the pipe inside finished walls and a ceiling, then patching and restoring those finishes, takes real time. A finished basement job costs more than the same system run through an open mechanical room.
Testing comes first, and it is cheap
You cannot price a radon fix without a radon number, and you cannot know your number without a test. Radon is invisible and has no smell, so a test is the only way to find it.
New Hampshire makes the first step easy. The state Radon Program offers free radon air-test kits, and the NH Department of Environmental Services is plain about why everyone should use one: “any home, any age, anywhere in the state” can have radon. A free do-it-yourself kit is a fine way to find out whether you have a problem.
When you are ready to design a fix, a professional test from 603 is $50. That gives us the accurate, current reading the system is built around — and if you go ahead with the mitigation, that $50 is credited toward the job.
Why NH homes need this more than most
New Hampshire sits on granite bedrock, and that is the problem. Radon is a radioactive gas produced naturally as uranium in rock and soil breaks down, and the Granite State’s geology makes elevated radon common statewide. NH DES estimates long-term radon exposure causes about 100 deaths in the state each year.
The health stakes are why this matters. The EPA reports that radon is the second-leading cause of lung cancer in the United States and the number-one cause among people who never smoked, linked to about 21,000 lung-cancer deaths a year — roughly 2,900 of them in people who never smoked.
The number you are testing against is set by the EPA. The EPA recommends fixing a home at 4 pCi/L or higher and considering a fix between 2 and 4 pCi/L, and it is clear there is no known safe level of radon. For reference, the average indoor level in the U.S. is about 1.3 pCi/L, and the EPA estimates about 1 in 15 U.S. homes has an elevated level. Once you have your reading, the page on radon levels in New Hampshire walks through what each number means.
Why a pro install, and what 603 backs it with
A radon system looks like a fan and some pipe. It is not. Get the suction point in the wrong place, undersize the fan, fail to seal the slab penetrations or the floor-wall joint, vent it too low or too close to a window, and you end up with a system that runs, makes noise, costs you electricity, and does not actually drop your level. A botched DIY install is exactly how that happens.
We are state-certified for radon mitigation (cert # RMS-113966), licensed and insured. Our radon work is run by Branden, who has been at this a long time. Every radon mitigation system we install carries a 10-year warranty on the system’s integrity and components. One honest caveat, stated plainly: that warranty covers the system, not a guaranteed radon number, unless a specific level is put in writing on your contract. How the system itself works is covered on our radon mitigation systems page.
Frequently asked questions
How much does a radon mitigation system cost in New Hampshire?
The 603 NH range is $900 to $6,000, and most homes land around $1,950 to $2,250. A single suction point on an open basement is the low end; a large home, a finished basement, a crawl space, or a very high reading is the high end. Radon testing is separate, about $50.
Why does the price range so much, from $900 to $6,000?
Foundation type, home size, the number of suction points, fan size, and whether the system has to route through a finished basement or a crawl space. A clean open slab with one suction point is cheap. A fieldstone foundation, a crawl space, or a finished basement with high radon costs more.
How much does radon testing cost, and is it separate from mitigation?
New Hampshire offers free radon air-test kits through the state Radon Program, so you can find out for nothing. A professional test from 603 is $50, separate from any mitigation. You test first, because the reading decides how the system is designed.
What radon level means I need a mitigation system?
The EPA recommends fixing a home at 4 pCi/L or higher and considering a fix between 2 and 4 pCi/L. There is no known safe level of radon, so lower is always better.
Does a radon system come with a warranty, and is the radon level guaranteed?
Our radon mitigation systems carry a 10-year warranty on the system’s integrity and components. The warranty covers the system, not a guaranteed radon number, unless a specific level is written into your contract.
Can you put a radon system in a crawl space or a fieldstone basement?
A crawl space or dirt floor uses a sealed membrane system instead of slab suction, and older NH homes with fieldstone foundations are exactly the kind of work we specialize in.
Ready to get your number?
Start with a test. If your reading is high, we will design a system around it and put a written quote in your hands within 24 hours. The inspection and the estimate are free. Get in touch and we will get you sorted!
