Radon Contractor vs Home Inspector: Who Should You Hire?

You just got a real estate contract accepted, and the clock is ticking on inspections. Radon testing is on the list. Do you let the home inspector handle it, or do you bring in a separate radon professional? The answer matters more than most buyers realize.

What Home Inspectors Actually Do with Radon

A general home inspector evaluates roofing, plumbing, electrical, HVAC, structure, and a dozen other systems in a few hours. Radon testing is one small add-on in a very long checklist. Most inspectors who offer radon testing will place a continuous radon monitor (CRM) during the inspection and pick it up 48 hours later.

That process can produce valid results. But here is the thing — the quality depends entirely on the inspector's training and equipment. Some inspectors carry NRPP or NRSB certification for radon measurement. Many do not. In states without strict licensing requirements, a home inspector can legally place a radon device with no radon-specific credential at all.

What inspectors generally cannot do is design or install a mitigation system. If the test comes back high, you are calling a radon contractor anyway.

What a Dedicated Radon Professional Brings

A certified radon contractor — typically credentialed through NRPP (National Radon Proficiency Program) or NRSB (National Radon Safety Board) — specializes in radon measurement and mitigation. This is their entire business, not a $150 add-on to a general inspection.

The practical differences:

• Equipment. Radon professionals typically use commercial-grade continuous monitors with tamper-detection and hourly logging. Some inspectors use the same equipment; others use lower-end devices.
• Protocol knowledge. A certified pro follows EPA/ANSI-AARST measurement protocols precisely — closed-house conditions, device placement height, distance from walls, and documentation standards. These details affect result accuracy.
• Mitigation expertise. If the test is elevated, a radon contractor can assess the foundation and give you a mitigation estimate on the spot. An inspector has to refer you out.
• Defensible results. In a real estate negotiation, a test performed by a certified radon measurement professional carries more weight than one performed by a generalist. Sellers and their agents are less likely to challenge it.

We cover how we evaluate contractor credentials in detail on our methodology page, which explains the certification standards we verify.

The Conflict of Interest Question

Fair warning: this topic generates strong opinions. Some people argue that a radon contractor who both tests and mitigates has a financial incentive to find high results. If they get a high reading, they get a mitigation job.

That concern is not entirely unfounded. But in practice, certified radon professionals stake their credential on accurate results. NRPP and NRSB both require adherence to measurement protocols, and falsifying results risks losing the certification that allows them to operate. Most reputable contractors separate their measurement and mitigation pricing specifically to avoid this perception.

On the other side, a home inspector who bundles radon testing for a low fee may not have the same investment in getting the measurement right. Their primary relationship is with the buyer, and a clean radon result makes the transaction smoother for everyone — including them.

Neither arrangement is automatically better. What matters is verifiable certification and transparent protocols. Ask anyone you hire: what credential do you hold, what device are you using, and can I see the full data log after the test?

Cost Comparison

Here is what you are typically looking at:

• Home inspector add-on: $100 to $200 on top of the general inspection fee. Some inspectors include it in a package deal.
• Dedicated radon professional: $150 to $300 for a standalone 48-hour CRM test with a full report.

The price gap is often $50 to $150. On a home purchase worth $300,000 or more, that difference is noise. If the extra cost buys you a more defensible result and direct access to a mitigation expert if needed, it is a reasonable investment. Our complete testing guide walks through the full process and what to expect.

When the Inspector Route Makes Sense

There are situations where letting the home inspector handle radon is perfectly fine:

• The inspector holds a current NRPP or NRSB measurement certification (ask for the ID number and verify it).
• You are in a low-risk area and testing is more of a precaution than an expectation.
• The inspection timeline is tight and coordinating a separate radon professional adds scheduling complications.

When You Need a Dedicated Radon Pro

Bring in a specialist when:

• The home is in a Zone 1 area (EPA's highest radon potential designation).
• There is already a mitigation system installed and you need to verify it is working — that requires someone who understands system diagnostics.
• You want post-closing mitigation and prefer the same person who tested to design the fix.
• The seller disputes a high result from the general inspector and you need a second test from a certified professional.

For finding credentialed contractors in your area, our contractor directory verifies NRPP and NRSB status so you do not have to. And if you want a deeper breakdown of what separates good contractors from mediocre ones, read how to choose a radon mitigation contractor.

The Straightforward Answer

If your home inspector has a current radon measurement certification and uses a commercial-grade CRM, they can handle testing just fine. If they do not — or if you are buying in a high-radon area and want the strongest possible data — spend the extra money on a dedicated radon professional. The cost difference is trivial compared to the health and financial stakes of getting it wrong.