Radon in Real Estate

Radon testing and mitigation are not required during real estate transactions, but testing is highly recommended. MDH recommends a licensed radon professional conduct testing during real estate transactions when an unbiased third-party is desired. Buyers and sellers in a real estate transaction can negotiate radon testing, radon mitigation system installation, and who is responsible for the costs. Ultimately, it is up to the buyer to decide what is an acceptable level of radon.

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Radon in Real Estate Transactions (PDF)

Disclosure requirements

The Minnesota Radon Awareness Act requires specific disclosure and education be provided to potential home buyers during residential real estate transactions in Minnesota. Before signing a purchase agreement to sell or transfer residential real property, the seller shall disclose, in writing to the buyer, any knowledge the seller has of radon concentrations in the dwelling. The disclosure shall include:

1. Whether a radon test or tests have occurred on the property;
2. the most current records and reports pertaining to radon concentrations within the dwelling;
3. a description of any radon concentrations, mitigation, or remediation;
4. information regarding the radon mitigation system, including system description and documentation, if such system has been installed in the dwelling; and
5. a radon warning statement; and
6. a copy of the Minnesota Department of Health publication entitled "Radon in Real Estate Transactions."

The MN Department of Health (MDH) is aware that private trade organizations have created forms to facilitate the radon disclosure including the Minnesota Association of Realtors and the Minnesota State Bar Association (MSBA). Individuals may create their own disclosure that meets the requirements of the Minnesota Radon Awareness Act. As a sample of a radon disclosure that meets the disclosure requirements of the Minnesota Radon Awareness Act, the MDH is providing the MSBA Model Radon Disclosure Form: MSBA Radon Disclosure Real Property Form 24 (PDF).

Radon Warning Statement
“The Minnesota Department of Health strongly recommends that ALL homebuyers have an indoor radon test performed prior to purchase or taking occupancy and recommends having the radon levels mitigated if elevated radon concentrations are found. Elevated radon concentrations can easily be reduced by a licensed radon mitigation professional. Every buyer of any interest in residential real property is notified that the property may present exposure to dangerous levels of indoor radon gas that may place the occupants at risk of developing radon-induced lung cancer. Radon, a Class A human carcinogen, is the leading cause of lung cancer in nonsmokers and the second leading cause overall. The seller of any interest in residential real property is required to provide the buyer with any information on radon test results of the dwelling.”

Radon testing procedures

Any real estate testing requires closed-house conditions. This means keeping all windows and exterior doors closed, except for normal entry and exit. Operate home heating or cooling systems normally during the test. Radon tests conducted during a real estate transaction should be done in the lowest level of home that is occupiable (such as the basement or a room above a crawl space) for each foundation of the home. The lowest level is typically the basement, whether finished or unfinished.

How to test

There are special procedures for radon testing in real estate transactions. A licensed radon measurement professional should conduct the test and produce a report. Tests are done for a minimum of 48 hours. When time is limited there are two testing options.

Continuous Radon Monitor This calibrated electronic monitor measures hourly levels. Other data may also be collected to ensure a valid test. Tests are done for minimum of 48 hours. Licensed professionals can perform this test.	Simultaneous short-term testing Two short-term test kits are used at the same time, placed 4 inches apart. Tests are sent to a laboratory for analysis. The two test results are averaged to give an overall radon level.

Recommendations for buyers

If the home has been tested, the buyer must decide the results of the past test(s) are acceptable. Items to consider include:

• What was the radon level and is it near the 4.0 pCi/L action level?
• Was the test set up for the minimum time required?
• Was the test done in the last 2 to 5 years?
• Was the basement tested if it was livable?
• Did the homeowner or licensed professional perform the test?

If the home has NOT been tested, the buyer should decide if they wish to request testing. If yes, some items to consider include:

• Will a licensed professional perform the test?
• Will a calibrated continuous radon monitor be used?
• Will the lowest livable area of each foundation be tested?
• How will the results be shared?
• At what level will a radon mitigation system be installed?
• Who will pay for the testing and installation of the radon mitigation system?

Recommendations to sellers

As a seller, consider the benefits of testing your house well before you put it on the market, as opposed to waiting until you are in the middle of the sale. If you find a problem that should be fixed, you will have time to get it corrected. You also may get a better price for the home because properly conducted radon tests and a radon mitigation system can be used as positive selling features of the home.

Recommendations for real estate professionals 

Real estate professionals play an important role, by facilitating radon awareness, accurate testing, and effective mitigation.

Sellers must disclose and notify buyers. 

Check that your disclosure packet has the radon questions (above) and the current 2-page Radon in Real Estate Transactions publication. This information may prompt a buyer to have a radon test conducted, for example, during the home inspection. 

Recommend a radon test to your clients, conducted by a MDH licensed professional. 

Testing by an independent expert is recommended in home sales. The Radon Licensing Act requires anyone who performs a radon test or radon mitigation, in a building they do not own or lease, must be licensed by MDH. Industry or other certification is not sufficient. Ask the professional for a copy of their license or check the current listing, Find a Radon Measurement Professional.

Test with closed house conditions. 

Radon Professionals notify sellers about closed house conditions and request the notification forms is signed. This helps ensure the results are accurate.  Failure to maintain closed house conditions can result in delays and additional cost. For more information, see the example Radon Test Notification Form (radon professionals use this for or an equivalent). Ask your seller to review and sign the radon notification form provided by the professional. 

Radon professionals test each foundation. 

To evaluate the radon risk, measurement professionals test each foundation type. Tell the measurement professional how many foundation types are present in the home (basement, crawl space, slab on grade), so they bring enough devices to conduct testing.

MDH conducts free inspections of mitigation systems installations.

Mitigation professionals must affix a MDH issued tag once a system is complete. Check that a MDH tag is affixed to each mitigation system. Homeowners can request a free inspection of mitigation systems installed by professionals in existing buildings, since June 1, 2020. MDH staff can check that an installed system meets standards and is effective, durable, and safe. Promote the mitigation inspection service to your clients.

MDH offers free continuing education.

Indoor air classes are taught in-person, at real estate offices and associations. We offer three classes approved by the MN Department of Commerce for real estate continuing education: radon (1.5 hr), mold (1 hr), and carbon monoxide (1 hr). Ask your education coordinator to contact the MDH Indoor Air Unit to schedule classes. 

MDH also offers an on-demand, free, 2-hour real estate continuing education class about well water: ‘Be a Well Savvy Real Estate Professional’. It is available a the MDH Learning Center (login and search the catalog).