Radon (Ionizing Radiation)

Radon is a natural, radioactive noble gas. It penetrates buildings from underground through cracks, crevices, leaky joints and natural floors. After smoking, radon is the second most important triggering factor of lung cancer in Switzerland.

The Swiss Radiation Protection Ordinance (StSV), SR 814.501, is also directly applicable in Liechtenstein. According to Art. 155 StSV, a radon reference value of 300 Bq/m³ applies to "rooms in which persons regularly spend several hours per day". These can be, for example, living rooms, school rooms, kindergartens or workplaces. If the radon reference value is exceeded, the building owner shall take the necessary remediation measures according to Art. 166 para. 1 StSV. The costs of the remediation shall be borne by the owner in accordance with Art. 166 Para. 4 StSV.

• Natural floors in the basement only with additional protective measures
• Living spaces directly above ground only with additional protective measures
• Continuous foundation slab instead of strip foundations
• When preheating air in the ground, the outside air must be routed through gas-tight pipes
• With careful moisture protection, radon penetration is effectively prevented
• Carefully seal penetrations for pipes of all types and installation ducts
• Suction of soil air with a perforated pipe system
• Sealed stairwells, tight doors with automatic door closers between basement rooms and living areas

• Sealing of penetration points: Cracks, leaking joints, manholes, installation penetrations
• Sealing measures between basement and living areas
• Suction of soil air with a radon well
• Injection of a small amount of fresh air into individual living spaces
• Extracting infiltrating radon from the basement with an exhaust system

In certain situations, such as complex construction projects or geologically challenging conditions, it is recommended that the building owner consult a radon specialist 

For new construction projects or major remodeling projects, it is recommended that the topic of radon be included in the construction contracts.

The undersigned (building owner or representative with power of attorney) confirms that the necessary measures for protection against elevated radon gas concentrations are taken in accordance with the recognized rules of building science.

Form: Declaration by Building Owner Protection from Elevated Radon Gas Concentrations