Radon removal

Radon extraction (also known as radon suction or radon drainage) is a structural measure used to extract the naturally occurring radioactive noble gas radon from the ground and discharge it into the open air before it can enter indoor spaces. Radon is produced by the radioactive decay of uranium and radium in the soil and is considered the second leading cause of lung cancer in Germany after smoking. Since the Radiation Protection Act of 2017, building owners in designated radon prevention areas are required to conduct measurements and, if necessary, carry out remediation.

How does radon extraction work technically?

The core principle of active radon extraction is the creation of negative pressure beneath the building. A perforated pipe system is installed in the area of the foundation or floor slab, which continuously extracts air from the subsoil via a fan. The radon-containing gas is directed outdoors through a vertical pipe, where it safely dilutes into the outside air. The passive method does not use a fan but relies on natural thermal currents and wind pressure differentials; this method is particularly suitable for new buildings with a well-permeable drainage layer beneath the floor slab. In addition, sealing measures are applied to cracks in the floor slab, and indoor ventilation is improved.

Legal Framework and Limit Values

Since 2019, the Radiation Protection Act (StrlSchG) and the Radiation Protection Ordinance (StrlSchV) have established a reference value of 300 becquerels per cubic meter (Bq/m³) for indoor spaces. If this value is exceeded, owners of workplaces are required to take protective measures. While there is no legal obligation to remediate residential buildings, states must designate radon precautionary areas where statistically elevated radon concentrations are expected. The Federal Office for Radiation Protection (BfS) provides a radon map showing the exposure levels for each region. When selling real estate, an elevated radon level must be disclosed to the buyer as a known material defect.

Costs, Planning, and Funding

A professional radon measurement by an accredited service provider costs €100-300. The subsequent remediation through active radon extraction costs €1,500-8,000, depending on the building’s size and soil conditions. The federal states and the BfS offer information programs; some development banks provide financing through energy efficiency or renovation programs. To plan effective radon abatement, a specialized company with experience in radon remediation must be hired; simple ventilation measures alone are generally insufficient for high radon levels.

Radon as a Disclosure Requirement in Real Estate Sales

If a seller is aware that the radon reference value of 300 Bq/m³ is exceeded in their property, failure to disclose this information constitutes a material defect concealed with fraudulent intent. According to Section 444 of the German Civil Code (BGB), invoking a contractually agreed warranty exclusion is not permitted in cases of fraudulent concealment. Buyers may then claim damages, a price reduction, or even rescind the purchase contract. Sellers who have conducted a radon measurement or are aware of radon levels should therefore document this information in the purchase contract or in an attached handover report. Transparency protects both parties and prevents costly disputes after the sale.

Practical Tip for Property Owners in Nuremberg and Franconia

The geological conditions in parts of Franconia-particularly in the Fichtelgebirge, the Franconian Forest, and the northern district of Tirschenreuth-exhibit elevated natural background radon levels. However, there are also individual areas with uranium-bearing subsoil in Nuremberg and the greater Erlangen-Höchstadt region. We recommend that owners of older basement and ground-floor apartments in Franconia conduct a long-term measurement (at least three months) before renovating or selling. The Bavarian State Office for the Environment (LfU) offers free consultation and provides measurement kits for homeowners.

When purchasing a property in the region, you should actively address the issue of radon as part of the due diligence process-we can advise you on which questions to ask the seller. For owners looking to renovate, it is worthwhile to combine radon abatement with ongoing basement renovation work: Installing the abatement pipe system at the same time saves significant time and costs compared to a separate, retroactive measure. Contact us if you are looking to buy or sell a property in a potentially radon-contaminated location in Franconia-we will support you with the necessary technical expertise.

Frequently Asked Questions

How long does a radon measurement take before ventilation can be planned?

For a representative long-term measurement, the Federal Office for Radiation Protection recommends a measurement period of at least three months, ideally during the heating season (October to April), as buildings are more tightly sealed then and radon can accumulate more easily. Rapid tests are available within a few days, but they do not provide statistically reliable values and are insufficient for official documentation.

As a landlord, do I have to inform my tenants about radon?

There is currently no legal obligation to inform tenants unless the reference value is exceeded in workplaces. For residential properties, however, proactive information and documentation of measurement results are recommended for liability reasons, as known health risks can be considered a defect in the property. Under tenancy law, a tenant could claim a rent reduction if high radon concentrations are proven.

Can radon abatement be combined with basement renovation?

Yes, and this often makes economic sense. If sealing work on the basement or floor slab renovation is planned anyway, the piping system for radon abatement can be integrated with significantly less effort. We recommend always including radon protection in the planning of basement and foundation renovations and involving a specialized contractor early in the construction planning process.

Which specialized contractors are responsible for radon abatement?

There is no generally recognized certification for radon remediation companies in Germany; however, the Federal Office for Radiation Protection offers a database of qualified professionals. For professional radon abatement, you should hire specialized contractors with experience in sealing techniques, drainage systems, and ventilation systems-these are often specialized construction companies or building services firms with relevant experience. In Franconia, the Bavarian State Office for the Environment (LfU) recommends local contacts in the region. At my-home.de, we can, upon request, put you in touch with suitable specialized companies in the Nuremberg metropolitan area that have already conducted radon measurements and remediation projects in the region.

Radon as a Due Diligence Issue for Commercial Real Estate

While radon remains primarily a matter of recommendation for residential buildings, it is a legal obligation for workplaces. Under Section 127 of the Radiation Protection Act (StrlSchG), employers are required to measure radon concentrations at workplaces if these are located in basements, ground floors, or in designated radon precautionary areas. In commercial real estate transactions-office buildings, production facilities, retail spaces-radon exposure should therefore routinely be part of the technical due diligence process. Failure to measure radon in a commercial property can lead to significant liability risks for the owner and landlord in the event of damage-for example, if an employee falls ill after many years of radon exposure. We recommend systematically integrating radon assessment into the technical inspection process when evaluating and transacting commercial real estate in Nuremberg and Franconia.

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