What a radon testing covers
Radon testing measures the long-term average radon-gas concentration in a property using passive detectors placed in occupied rooms, typically the bedroom and main living room, over a 3-month period. Results are reported in becquerels per cubic metre (Bq/m³); UK action level is 200 Bq/m³, target level is 100 Bq/m³.
- Two passive detectors deployed for 90 days minimum
- Detector placement in occupied rooms per UK guidance
- Annual-mean correction applied to seasonal exposure
- UKHSA-validated laboratory analysis
- Written report with action-level interpretation
- Recommendations on remediation if levels exceed action level
Typical findings
- Most UK properties below 100 Bq/m³ target level
- Properties in radon-affected areas (Cornwall, Devon, parts of Derbyshire, Northamptonshire) commonly above target
- 1-3% of properties in affected areas above 200 Bq/m³ action level
- Sub-floor void radon ingress as the dominant pathway in older stock
- Ground-floor concentration significantly higher than upper floors
Typical cost: £50-£120 standard 3-month UKHSA test, £180-£350 with rapid testing or detailed remediation advice
When to book: If the property is in a radon-affected area on UKHSA's geological risk map, before purchasing in such an area, after major renovations to a basement or ground floor, or where occupant respiratory symptoms are unexplained.
Required qualifications for assessor: UKHSA-validated radon-measurement service, surveyor trained in radon assessment per UKHSA guidance