Real Estate Radon Measurement
- Home
- Real Estate Radon Measurement

🏠 Real Estate RADON Screening Process (CARST Guideline)
| Step | Action | Condition | Result | Next Step |
|---|---|---|---|---|
1️⃣Perform RADON Screening Test |
minimum 4-day test | |||
2️⃣Interpret Results |
Compare with guideline thresholds. | “Green”, “Yellow”, or “Red” result | Follow corresponding action below. | |
| 🟢 Green Result | ≤ 75 Bq/m³ (heating season) or ≤ 50 Bq/m³ (non-heating season) |
Sale proceeds normally. | Perform a long-term test after move-in. | |
| 🟡 Yellow Result | > 75/50 Bq/m³ and ≤ 400 Bq/m³ |
Include possible mitigation allowances in the purchase agreement. | Buyer conducts a long-term test | |
| 🔴 Red Result | > 400 Bq/m³ | Negotiate cost for mitigation system | Mitigation completed within 12 months; | |
3️⃣Long-Term Confirmation |
Buyer performs long-term test after occupancy. | ≤ 200 Bq/m³ → Safe > 200 Bq/m³ → Mitigate. | Re-test every 3 years. |
🏠
Real Estate Radon Measurement Process Chart
🏠 Real Estate Radon Measurement Process Chart

CARST Guideline for Conducting a Radon Screening Assessment
CARST Guideline for Conducting
a Radon Screening Assessment
