What the problem is
Radon concentration is invisible and highly variable. Two houses on the same street, built by the same builder, can differ by a factor of five. Concentration also changes with season, weather, and how the house is being operated. A measurement is only meaningful when it is taken under controlled conditions with a device that is calibrated and correctly placed.
How to know if you need a test
- You have never tested. That alone is reason enough — the EPA recommends every home be tested.
- You are buying or selling a home.
- You finished a basement, added a room, or changed the HVAC system.
- Your last test was more than two years ago.
- You have an existing mitigation system and want to confirm it is still performing.
How the measurement is made
Two categories of device are used, and the right choice depends on what decision the result has to support.
| Method | Duration | Best for |
|---|---|---|
| Continuous radon monitor (CRM) | 48 hours | Real estate transactions — records hourly readings, detects tampering, no lab delay |
| Short-term passive (charcoal, alpha track) | 2–7 days | A fast first screen of an occupied home |
| Long-term passive (alpha track) | 90 days – 1 year | The most accurate picture of annual average exposure |
Placement rules that determine whether a test is valid
- Lowest lived-in level of the home — a basement if it is used, otherwise the ground floor.
- 20 inches to 6 feet above the floor, at least 3 feet from exterior walls and windows.
- Away from drafts, heat, direct sun, and high humidity.
- Not in a kitchen, bathroom, laundry, or closet.
Closed-house conditions
Twelve hours before the test starts and for its entire duration, exterior windows and doors stay closed except for normal entry and exit. Whole-house fans, window fans, and evaporative (swamp) coolers stay off, since they change ventilation dramatically — a common source of misleading results in New Mexico homes. Normal HVAC operation is fine.
Expected timeline
- 112 hours of closed-house conditions before deployment.
- 248 hours of measurement for a short-term test.
- 3Same-day report with a continuous monitor; 3–7 days if a passive device goes to a lab.
- 4If the result is elevated, mitigation can usually be scheduled within days.
How to read your result
pCi/L reference table
Levels reflect EPA guidance for residential indoor air.
| Level | What it means | Recommended action |
|---|---|---|
| 0.0 – 1.9 pCi/L | At or below typical US indoor average (1.3 pCi/L) | No action needed. Retest in about two years. |
| 2.0 – 3.9 pCi/L | Elevated but below the action level | EPA suggests considering mitigation. A long-term test helps confirm. |
| 4.0 – 7.9 pCi/L | At or above the EPA action level | Mitigation recommended. |
| 8.0 – 19.9 pCi/L | Two to five times the action level | Mitigate promptly. |
| 20+ pCi/L | Substantially elevated | Treat as urgent; mitigate as soon as possible. |
Should I mitigate?
Guidance based on EPA action levels. Your specific situation may vary.
Mitigation recommended
You are at or above the EPA action level of 4.0 pCi/L. The EPA recommends fixing homes at this level.
What affects the cost
- Device type — a continuous monitor deployment costs more than a passive kit.
- Number of measurement locations (large homes and multiple foundation types need more).
- Whether a written report for a real estate transaction is required.
- Travel distance outside the core Albuquerque and Rio Rancho service area.
What happens after the test
You get the measured value, the test conditions, the device used, and a plain-language explanation of what it means. If the result is below 2.0 pCi/L, the recommendation is simply to retest in two years. Between 2.0 and 4.0, you have a real choice to make and we will walk you through it rather than push a system. At or above 4.0, we will explain what a mitigation design for your specific foundation would involve.
Common questions
A quality charcoal or alpha-track kit is reasonably accurate when the placement and closed-house rules are followed exactly. The failure mode is procedure, not the device. For a real estate transaction, most parties require a professional continuous monitor test instead.
Related services
Keep learning
- Radon Testing Methods ComparedEvery radon test measures the same thing, but the method determines how much you can trust the number and what decisions it can support.
- EPA Radon Action Levels ExplainedTwo numbers drive nearly every radon decision: 4.0 pCi/L, where the EPA recommends action, and 2.0 pCi/L, where it suggests considering it. Here is what sits behind them.
- Radon Health Risks: What the Evidence ShowsRadon is the second leading cause of lung cancer in the United States. The mechanism is well understood, and the risk scales with concentration and time.