Choosing a contractor
How do I tell a good radon contractor from a confident one?
The order here is not negotiable, and it is the opposite of how most homeowners do it. Credential verification is fast, free, and disqualifying — so it goes first, before you have invested any time in comparing prices from someone who should not be on the list.
After that it is reading comprehension. Two proposals for the same house differ mostly in what they leave unwritten, and the questions below exist to force the unwritten parts onto paper before you sign anything.
Who this is for. Someone with one to three proposals in hand, or about to start collecting them.
The reading order
5 steps, 17 resources. Nothing below is written here — every link goes to the page that holds the substance, and the note under each one says what it adds at that point in the sequence. A hub that restated its own links would just be competing with them.
Verify the credential yourself
A credential you have not checked with the issuing authority is a claim on a website. This takes minutes and eliminates the worst outcomes.
- NRPP certification Guide
What this credential covers, who issues it, and how to confirm a specific person holds it today.
- NRSB certification Guide
The other national credential, what differs, and why a contractor may hold one and not the other.
- State certification differences Guide
State licensing is separate from national certification, and in some states it is the one that legally matters.
- Licensed contractors in Illinois Page
The Illinois case in full, including where the official licensee list lives.
- State Radon Regulatory Index Dataset
Which regime applies in each state we cover, as structured data with the authority for each entry.
- NRPP certification Guide
Ask the questions that force specifics
A proposal becomes comparable only after the vague parts have been made explicit. These are the questions that do that.
- Questions to ask before hiring Guide
The full list with the reasoning for each, so you can tell which answers are actually disqualifying.
- Before hiring Checklist
The same ground, printable, for a conversation happening in your basement rather than at your desk.
- Why experience matters Guide
What experience changes in practice, which is mostly diagnostics and unusual foundations.
- Questions to ask before hiring Guide
Compare the proposals line by line
The cheaper bid is sometimes the better one and sometimes an incomplete scope. The difference is visible once the lines are aligned.
- Compare two quotes Tool
Aligns two proposals on the lines that actually vary, and flags what is missing from each rather than which is cheaper.
- Radon Quote Line-Item Comparison Dataset Dataset
The line items themselves, defined, so an omission is recognisable as an omission.
- Comparing radon contractors Guide
How to weigh scope, warranty, and verification against price without pretending they are the same axis.
- How to choose a radon contractor Guide
The whole decision end to end, useful once the individual pieces above make sense.
- Compare two quotes Tool
Recognise what should end the conversation
A small set of behaviours reliably predicts a bad outcome. Knowing them turns an uncomfortable feeling into a decision.
- Red flags when hiring Guide
The specific behaviours, and what each one usually indicates about how the job will go.
- Cheapest vs best contractor Guide
Why the lowest bid is a legitimate choice in some situations and a trap in others.
- Sales tactics, explained Page
The pressure techniques written out plainly, from the same material we give contractors in our network.
- Red flags when hiring Guide
When you want another opinion
A second proposal is worth the delay in some situations and not in others, and the deciding factor is usually what is unclear rather than what is expensive.
- Do I need a second opinion? Tool
Works through whether another proposal would actually change your decision, which is the only reason to wait for one.
- Contractor Response Time Dataset Dataset
A published instrument with no observations yet, and its methodology says so. Read it as a schema rather than a finding.
- Do I need a second opinion? Tool
What you should be able to do afterwards
- Confirm a credential with the issuing authority before comparing prices.
- Turn a vague proposal into a comparable one by asking three or four specific questions.
- Identify what a cheaper bid has left out.
- Decide whether another opinion would change anything.
Related hubs
- Mitigation systems — A pipe and a fan is not a design. This is the difference.
- Costs and value — We explain what moves a price. We do not publish one we have not measured.
- State regulations — Almost nothing about radon is federal law. Nearly all of it is state practice.
- All nine hubs — the full learning centre.
Confidence and limits of this page
Every decision resource on this platform states its own boundaries. This is not a disclaimer — it is the part of this hub you should read before relying on it.
- What we knowClaims on this page we stand behind, each traceable to an approved source or to observable structure.
- National certification and state licensing are separate regimes, and which one legally governs depends on the state.
- Illinois requires measurement and mitigation professionals to be licensed, under the statute we cite, and the state programme publishes a licensee list.
- Proposals for the same house commonly differ in scope, verification, and warranty rather than only in price, which is why line-by-line comparison changes conclusions.
- What we do not knowQuestions you may reasonably have that this page does not answer.
- Whether any specific contractor is competent. Credential verification establishes a floor, not quality, and we hold no performance observations on individual firms.
- How quickly contractors in a given market respond to a request, which is the instrument we have published and not yet filled.
- What research would settle itWhat it would actually take to answer the above — naming it is the difference between honesty and hedging.
- Recorded proposal-to-outcome pairs across many jobs, which would let anyone say which proposal features predict a working system.
- Response-time observations at scale, which is the collection instrument published in our research centre with an explicit count of zero.
- What we do not claimClaims you might expect to find here and will not, with the reason.
- We do not rank, rate, score, or recommend individual contractors anywhere on this platform, and no page here names a best company.
- We do not claim a credential guarantees quality of work, because it establishes a verified minimum and nothing more.
- We do not publish contractor performance figures, because we hold no observations and inventing them would be the fabrication this platform exists to avoid.
- What we cannot independently verifyFacts this page relies on that we could not confirm ourselves.
- Whether a named individual currently holds a credential, which changes over time and only the issuing authority can confirm at the moment you ask.
- Any contractor own claims about crews, years in business, or job counts, none of which appear on this platform as facts.
Sources
- U.S. EPA — Consumer’s Guide to Radon Reduction
- IEMA-OHS — Illinois Emergency Management Agency and Office of Homeland Security — Radon Program
- Illinois General Assembly — Radon Industry Licensing Act (420 ILCS 44)
Get quotes from credentialed local contractors
Free to request and no obligation. We verify credentials with the issuing authority before any request routes to a contractor.