Radon FAQs

Radon FAQs

Radon is cancer-causing, radiative gas.

You cannot see, smell, or taste radon. But it still may be a problem in your home.  When you breathe air containing
radon, you increase your risk of getting lung cancer.  In fact, the Surgeon General of the United States has warned
that radon is the second leading cause of lung cancer in the United States today.  If you smoke and your home has
high radon levels, your risk of lung cancer is especially high.

You Should Test for Radon
Testing is the only way to find out your home’s radon levels. EPA and the Surgeon General recommend testing all
homes below the third floor for radon.

You Can Fix a Radon Problem
If you find that you have high radon levels, there are ways to fix a radon problem. Even very high levels can be
reduced to acceptable levels.

If You Are Selling a Home…
EPA recommends that you test your home before putting it on the market and, if necessary, lower your radon levels.
Save the test results and all information you have about steps that were taken to fix any problems. This could be a
positive selling point.

If You Are Buying a Home…
EPA recommends that you know what the indoor radon level is in any home you consider buying.  Ask the seller for
their radon test results.  If the home has a radon-reduction system, ask the seller for information they have about the

If the home has not yet been tested, you should have the housed tested.

If you are having a new home built, there are features that can be incorporated into your home during construction to
reduce radon levels.

The radon testing guidelines in this Guide have been developed specifically to deal with the time-sensitive nature of
home purchases and sales, and the potential for radon device interference.  These guidelines are slightly different
from the guidelines in other EPA publications which provide radon testing and reduction information for non-real
estate situations.

This Guide recommends three short-term testing options for real estate transactions.  EPA also recommends testing a
home in the lowest level which is currently suitable for occupancy, since a buyer may choose to live in a lower area of
the home than that used by the seller.

1. Radon Has Been Found In Homes All Over the U.S.

Radon is a radioactive gas that has been found in homes all over the United States. It comes from the natural

breakdown of uranium in soil, rock and water and gets into the air you breathe. Radon typically moves up through the

ground to the air above and into your home through cracks and other holes in the foundation. Radon can also enter

your home through well water. Your home can trap radon inside.

Any home can have a radon problem. This means new and old homes, well-sealed and drafty homes, and homes with

or without basements. In fact, you and your family are most likely to get your greatest radiation exposure at home.

That is where you spend most of your time.

Nearly 1 out of every 15 homes in the United States is estimated to have an elevated radon level (4 pCi/L or more).  

Elevated levels of radon gas have been found in homes in your state.  

2. EPA and the Surgeon General Recommend That You Test Your Home

Testing is the only way to know if you and your family are at risk from radon. EPA and the Surgeon General

recommend testing all homes below the third floor for radon.

You cannot predict radon levels based on state, local, and neighborhood radon measurements.  Do not rely on radon

test results taken in other homes in the neighborhood to estimate the radon level in your home.  Homes which are next

to each other can have different radon levels.  Testing is the only way to find out what your home’s radon level is.

In some areas, companies may offer different types of radon service agreements.  Some agreements let you pay a

one-time fee that covers both testing and radon mitigation, if needed.   

  • U.S. Surgeon General Health Advisory
  • “Indoor radon gas is the second-leading cause of lung cancer in the United States and breathing it over
  • prolonged periods can present a significant health risk to families all over the country.  It’s important to know
  • that this threat is completely preventable.  Radon can be detected with a simple test and fixed through well-
  • established venting techniques.”  January 2005

Testing For Radon

1. If Your Home Has Already Been Tested for Radon…

If you are thinking of selling your home and you have already tested your home for radon,  review the Radon Testing

Checklist to make sure that the test was done correctly.  If so, provide your test results to the buyer.

No matter what kind of test you took, a potential buyer may ask for a new test especially if:

  • The Radon Testing Checklist items were not met;
  • The last test is not recent, e.g., within two years;
  • You have renovated or altered your home since you tested; or
  • The buyer plans to live in a lower level of the house than was tested, such as a basement suitable for
    occupancy but not currently lived in.

A buyer may also ask for a new test if your state or local government requires disclosure of radon information to


2. If Your Home Has Not Yet Been Tested for Radon…

Have a test taken as soon as possible. If you can, test your home before putting it on the market.  You should test in

the lowest level of the home which is suitable for occupancy. This means testing in the lowest level that you currently

live in or a lower level not currently used, but which a buyer could use for living space without renovations.

The radon test result is important information about your home’s radon level.  Some states require radon

measurement testers to follow a specific testing protocol.  If you do the test yourself, you should carefully follow the

testing protocol for your area or EPA’s Radon Testing Checklist.  If you hire a contractor to test your residence,

protect yourself by hiring a qualified individual or company.

You can determine a service provider’s qualifications to perform radon measurements or to mitigate your home in

several ways.  Many states require radon professionals to be licensed, certified, or registered.  Most states can

provide you with a list of knowledgeable radon service providers doing business in the state.  In states that don’t

regulate radon services, ask the contractor if they hold a professional proficiency or certification credential. Such

programs usually provide members with a photo-ID card, which indicates their qualification(s) and its expiration date.  

If in doubt, you should check with their credentialing organization.  Alternatively, ask the contractor if they’ve

successfully completed formal training appropriate for testing or mitigation, e.g., a course in radon measurement or

radon mitigation.

1. If the Home Has Already Been Tested for Radon…

If you are thinking of buying a home, you may decide to accept an earlier  test result from the seller, or ask the seller

for a new test to be conducted by a  qualified   radon tester.  Before you accept the seller’s test, you should determine

the results of previous testing;

  • Who conducted the previous test:  the homeowner, a radon professional, or some other person
  • Where in the home the previous test was taken, especially if you may plan to live in a lower level of the home.  
    For example, the test may have been taken on the first floor.  However, if you want to use the basement as
    living space, test there…
  • What, if any, structural changes, alterations, or changes in the heating, ventilation, and air conditioning (HVAC)
    system have been made to the house since the test was done.  Such changes may affect radon levels.

If you accept the seller’s test, make sure that the test followed the Radon Testing Checklist.

If you decide that a new test is needed, discuss it with the seller as soon as possible.  

2. If the Home Has Not Yet Been Tested for Radon…

Make sure that a radon test is done as soon as possible. Consider including provisions in the contract specifying:

Where the test will be located

  • Who should conduct the test
  • What type of test to do
  • When to do the test
  • How the seller and the buyer will share the test results and test costs (if necessary)
  • When radon mitigation measures will be taken and who will pay for them.

Make sure that the test is done in the lowest level of the home suitable for occupancy. This means the lowest level

that you are going to use as living space which is finished or does not require renovations prior to use. A state or local

radon official or qualified radon tester can help you make some of these decisions.If you decide to finish or renovate

an unfinished area of the home in the future, a radon test should be taken before starting the project and after the

project is finished. Generally, it is less expensive to install a radon-reduction system before (or during) renovations

rather than afterwards.

1. Why Should I Buy a Radon-Resistant Home?

Radon-resistant techniques work.  When installed properly and completely, these simple and inexpensive passive

techniques can help to reduce radon levels.  In addition, installing them at the time of construction makes it easier to

reduce radon levels further if the passive techniques don’t reduce radon levels below 4 pCi/L.  Radon-resistant

techniques may also help to lower moisture levels and those of other soil-gases.  Radon-resistant techniques:

  • Making Upgrading Easy:  Even if built to be radon-resistant, every new home should be tested for radon after
    occupancy.  If you have a test result of 4 pCi/L or more, a vent fan can easily be added to the passive system to
    make it an active system and further reduce radon levels.
  • Are Cost-Effective:  Building radon-resistant features into the house during construction is easier and cheaper
    than fixing a radon problem from scratch later.  Let your builder know that radon-resistant features are easy to
    install using common building materials.
  • Save Money:  When installed properly and completely, radon-resistant techniques can also make your home
    more energy efficient and help you save on your energy costs.

In a new home, the cost to install passive radon-resistant features during construction is usually between $350 and

$500.  In some areas, the cost may be as low as $100.  A qualified mitigator will charge about $300 to add a vent fan

to a passive system, making it an active system and further reducing radon levels.  In an existing home, it usually

costs between $800 and $2,500 to install a radon mitigation system.