Radon testing in Virginia
Short-term vs long-term tests, DIY kits vs professional measurement, and the rules of the road when a test is part of a real-estate transaction.
We connect Virginia homeowners with licensed local radon professionals.
Why test at all
Radon is invisible and odorless, and levels vary house to house — two identical homes next door to each other can test wildly differently. The EPA’s zone map says where elevated levels are likely (much of northern and western Virginia), but the map explicitly is not a substitute for testing: every home should be tested regardless of zone.
Short-term vs long-term
- Short-term tests (2–7 days). Charcoal canisters or electret devices. Fast answer, more affected by weather and house conditions. This is what real-estate transactions use.
- Long-term tests (90+ days). Alpha-track detectors. Slower, but they average out seasonal swings and give the best picture of what you actually breathe year-round.
Short-term tests need closed-house conditions: windows shut, doors closed except for normal entry, starting 12 hours before the test. Running one with the windows open produces a comforting, useless number.
DIY kits vs professional measurement
Hardware-store and mail-order kits typically cost well under $50 including lab analysis, and they’re a legitimate first step for your own information. The Virginia Department of Health’s radon program periodically offers discounted kits — worth checking before you buy retail. Professional measurement uses a continuous radon monitor (CRM) that logs hourly readings and flags tampering — which is why transactions rely on it.
Virginia rule worth knowing: anyone paid to test or mitigate radon in Virginia must hold national certification (NRPP or NRSB). For a home sale, use a certified measurement professional — a DIY kit result generally won’t carry the negotiation.
Testing inside a real-estate deal
- The buyer’s inspection window is short — typically days, not weeks. A certified tester places a CRM for a minimum 48-hour test under closed-house conditions, following national (ANSI/AARST) protocols.
- At or above 4.0 pCi/L, buyers commonly ask the seller to mitigate or credit the cost. That’s where the published cost range becomes your negotiation anchor.
- After mitigation, a post-mitigation test verifies the fix — the paperwork both sides’ agents want in the file before closing. Systems are commonly installed within the contingency window; see how mitigation works for what gets built.
Reading your result
| Result | EPA guidance |
|---|---|
| Under 2 pCi/L | No action needed; re-test every couple of years and after major renovations. |
| 2–4 pCi/L | Consider mitigation — no radon level is considered risk-free. |
| 4.0 pCi/L or higher | Fix the home. Confirm with a follow-up test if time allows; act on the number if a deal is on the clock. |
Source: EPA, A Citizen’s Guide to Radon.
Already have a high result in hand? Homeowners in Prince William County and Fairfax most often reach us exactly at this step — the next move is quotes from certified mitigators.
Tested high? Get mitigation quotes
We connect Virginia homeowners with licensed local radon professionals.
If your result is at or above the action level — or you'd rather have a certified pro run the test — send the form and licensed local professionals will follow up directly.
- Free and no-obligation — you decide whether to hire anyone.
- Virginia law requires radon pros to hold national certification (NRPP or NRSB) — that is who your request goes to.
- On a closing deadline? Tick the box — deadline requests are flagged first.