A seller says the house was tested for radon. Before treating that as a complete answer, ask for the report. A result belongs to a particular test, in a particular part of the building, under particular conditions.
The US Environmental Protection Agency’s resources for home buyers and sellers recommend reviewing previous results, who conducted the test and where it was performed. Its guidance also asks about relevant changes to the building. Outside the US, use the corresponding local authority’s testing and transaction guidance.
Read the report as a record, not a reassuring label
Start with the address, test dates, duration, device or method and measurement location. Check the units rather than comparing a bare number with a threshold found on an unrelated website. Ask a qualified radon professional to explain any missing or unclear fields.
For example, suppose you intend to use a lower-level room as an office, but the available report describes a test upstairs. That is a useful question for the tester. It is not evidence that the lower room has either a high or a low result.
Likewise, a renovation after the test may matter. Tell the professional about alterations to the building or heating and ventilation arrangements instead of deciding for yourself that an older result must still apply.
Make the next step explicit
- Is the existing test suitable for this transaction and intended use?
- If another test is needed, who will arrange it and protect the required conditions?
- Who receives the report, and who explains any recommended action?
- If a reduction system exists, what installation and follow-up records are available?
Do not move, cover or interfere with an active test device. Follow the testing professional’s instructions, including the conditions required for that method. A disturbed test can waste the time you hoped to save.
Keep the radon discussion distinct from a general visual inspection. A tidy basement, open window or lack of unusual smell does not answer the measurement question. Save the report with the other property documents and record the agreed follow-up, so “tested” becomes a verifiable part of the purchase review.