A radon mitigation system from 603 runs $900 to $6,000, and most New Hampshire homes land around $1,950 to $2,250. A single suction point on an open basement is the low end; a large or finished home, a crawl space, or a very high reading is the high end. Testing comes first, and it is $50, credited toward the job if you go ahead, because nobody can price a fix until you know your number.
Radon mitigation cost at a glance (603, NH)
| What you have | Where it lands |
|---|---|
| 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 a very high reading | Upper end |
| Finished basement (pipe to hide) or a crawl space | Upper end, toward $6,000 |
The only way to your real number is an on-site look. 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 runs $900 to $6,000, with most homes 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. Maine and Massachusetts jobs sit in the same range, with older fieldstone foundations trending higher because they take more work to seal.
Testing is its own step, and it is cheap. A professional radon test from 603 is $50, separate from any mitigation, and if you go ahead with a fix that $50 is credited toward the job. You always test before you mitigate, because the level on the report decides how the system gets designed.
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.
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 out from under the slab before it reaches your living space. One suction point, one fan, one run of pipe. The simplest system, and it sits at the low end.
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. More pipe, more labor, and a larger fan move the price up.
Crawl-space membrane systems (upper end)
A dirt or fieldstone crawl space has no slab to vent through. Instead we seal the floor with a heavy membrane and pull the radon out from beneath it, called sub-membrane depressurization. Older New England homes with fieldstone foundations and half-basement, half-crawl layouts often need this, and 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 moves your number:
- Foundation type. A flat, open slab is the easy case. A fieldstone or rubble foundation has gaps and an uneven floor that make sealing and suction harder. A crawl space needs a membrane system. The harder it is to seal, the more it costs.
- Home size and slab area. A bigger floor means more pipe and often a stronger fan.
- Number of suction points. One hole is the base case. A second or third adds labor and materials, usually called for by a high reading or a chopped-up floor plan.
- Fan size and a monitor. A higher starting level needs a more powerful fan to get under the action level and hold it there. A continuous radon monitor can be part of the build.
- Routing through a finished basement. Hiding pipe inside finished walls and a ceiling, then patching the finishes, takes real time and costs more than 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 air-test kits, and NH DES is plain that “any home, any age, anywhere in the state” can have radon. When you are ready to design a fix, a professional test from 603 is $50, which gives us the accurate current reading the system is built around, credited toward the job if you proceed.
Why NH homes need this more than most
Radon is a radioactive gas produced naturally as uranium in rock and soil breaks down. It seeps up through the ground and collects in the lowest part of a house, and plenty of New Hampshire homes test high. NH DES estimates long-term radon exposure causes about 100 deaths in the state each year. The EPA reports 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 (US EPA).
The number you test against is set by the EPA: fix a home at 4 pCi/L or higher, and consider a fix between 2 and 4, with no known safe level (US EPA). Once you have your reading, our 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. Put the suction point in the wrong place, undersize the fan, fail to seal the slab or the floor wall joint, or vent it too low, and you end up with a system that runs, makes noise, costs you electricity, and does not actually drop your level. That is exactly how a botched DIY install goes.
603 is a state-certified radon contractor (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 written into your contract.
Frequently asked questions
How much does a radon mitigation system cost in New Hampshire?
A 603 radon mitigation system runs $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, at $50, credited toward the job if you proceed.
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 the cheap case. 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 and credited toward a fix if you proceed. 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?
Yes. A crawl space or dirt floor uses a sealed sub-membrane system instead of slab suction, and older NH homes with fieldstone foundations and crawl spaces are exactly the kind of work we do.
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 test is $50, credited toward the work if you move ahead, and the estimate is free. Call 603-610-1770 or schedule your free inspection.
