Radon: answers to your questions

Radon is a naturally occurring radioactive gas from the ground, invisible and odourless. It can enter through cracks, pipe penetrations or earth floors and accumulate in indoor air.

Yes. Prolonged exposure increases the risk of lung cancer. The FOPH identifies it as the second leading cause of this cancer in Switzerland after smoking. Risk depends on concentration and duration of exposure; it is higher for smokers.

Only a measurement can tell you. The FOPH map estimates the probability of exceeding the reference level without predicting the result for each home. Two neighbouring buildings can have different concentrations.

An in-depth survey involves approximately one week of simultaneous electronic measurements to understand the building. A recognised measurement using passive detectors runs over a longer period under the applicable protocol: in a home, one year is recommended, or at least 90 days during the heating season. We choose the approach according to your circumstances and timeframe.

A short-term survey examines concentrations and fluctuations across rooms to identify likely entry points and understand how radon moves through the building. A recognised measurement assesses the average concentration under the applicable protocol. The two methods can follow one another to prepare an intervention or confirm results.

We start with your situation. If an in-depth survey is appropriate, electronic monitors are installed simultaneously in all rooms and other spaces in contact with the ground, with additional points on upper floors depending on the building. If passive detectors are selected, they are placed in suitable rooms according to the protocol.

Yes. A year-long measurement also includes summer and can be recognised if the protocol is followed. However, a summer-only campaign does not meet the requirement for 90 days during the heating season. A short-term summer measurement remains an indication tied to its conditions.

It is the Swiss reference level for the annual average concentration in rooms where people regularly spend several hours a day. Bq/m³ expresses radioactive activity per volume of air. This level is not a boundary between risk and no risk: reducing exposure remains useful below it.

Send the report or the available results. We examine the method, duration, rooms and their occupancy. A technical survey can then provide the basis for suitable solutions. Where a recognised measurement establishes an exceedance of the reference level, the approach takes applicable requirements and any instructions from the authorities into account.

The next step depends on the method, duration, rooms and their occupancy. Following a short-term campaign with low concentrations or intermediate results, passive detectors can extend or confirm the assessment over a longer period. We also consider planned work and opportunities to reduce exposure.

The solution depends on entry routes and construction. It may combine extraction beneath the slab, suitable ventilation and sealing of air pathways. The survey helps select and size the intervention; a technique that works in one building will not automatically suit another.

The duration is specified in the quotation after the survey. It depends on access, the chosen solution, connections and any other trades involved. A standard timeframe cannot be given before the work has been defined.

Concentrations are monitored before and after the work to observe its effect and adjust the system if needed. A mitigation report presents the work and the results. A passive detector campaign is arranged to confirm them through a recognised measurement, according to the applicable schedule.

The price depends on the method, number of rooms and other spaces, floors to be examined and investigations. The quotation specifies the services, travel costs and VAT. For mitigation, monitoring before and after the work, the report and arrangements for confirmation using passive detectors are detailed in the quotation.

The necessary steps should be checked for the property and canton concerned. A recognised report documents the building’s situation; a short-term measurement cannot replace it. If an authority, buyer or notary requests a document, clarify that request before choosing a measurement method.

Under the Radiological Protection Ordinance, the owner bears the cost of necessary mitigation where the reference level is exceeded in the rooms concerned. To arrange and fund a measurement, particularly in rented property, first clarify the process with the owner and, if needed, the cantonal service.

Yes. Protection against radon entry must be considered at the design stage, including for alterations. Planning airtightness, service routes and ventilation helps avoid later remedial work. Check permit documents and required inspections with the competent authority.