Selling a house with radon

The guide splits a seller's advice by one question: has the home already been tested?

EPA also notes that a buyer may ask for a new test if your state or local government requires disclosure of radon information to buyers. Whether yours does is a state and local question; see radon disclosure.

EPA tells sellers to test in the lowest level of the home that could be used regularly. That means the lowest level you live in now, or a lower level you do not use but a buyer might use as a family room or play area. Buyers might want to know the level in a basement they plan to finish, EPA's Citizen's Guide notes, even if the seller would not otherwise test there.

Read this figure as textHide the text version

Test	How long it runs	What it is for
Short-term test	Stays in the home from 2 to 90 days, depending on the device, and for a minimum of 48 hours.	A faster screening result. Because radon levels vary from day to day and season to season, it is less likely than a long-term test to tell you the year-round average.
Long-term test	Stays in the home for more than 90 days.	It is more likely than a short-term test to tell you the home's year-round average radon level.
Continuous monitor	Logs readings for the whole test, run as a short-term or a long-term test under the same durations in EPA guidance.	Logs a graph over time, so you can see trends and spot anomalies rather than a single number.

Short-term or long-term before listing

Radon levels tend to vary from day to day and season to season, so EPA says a short-term test is less likely than a long-term test to tell you the year-round average. If you need results quickly, a short-term test may be used to decide whether to fix the home. A seller testing months ahead of a listing can run a long-term test of more than 90 days; one listing soon will use a short-term test of a minimum of 48 hours.

Doing the test yourself or hiring a tester

• Yourself. EPA says to follow the testing protocol for your area or EPA's Radon Testing Checklist carefully, and to use a device from a qualified laboratory. See radon test kits.
• A qualified tester. Some states require testers to follow a specific protocol, and many require radon professionals to be licensed, certified or registered. EPA says to check with your state radon office first.
• Credentials. In states that do not regulate radon services, EPA says to ask whether the tester holds a professional proficiency or certification credential. Such programs usually issue a photo ID showing the qualification and its expiration date.

EPA recommends fixing a home when the radon level is 4 pCi/L or higher. EPA recommends considering a fix when the level is between 2 and 4 pCi/L. EPA's Citizen's Guide says that if you find high radon levels, fix your home before you decide to sell it. Check a number with the radon result interpreter.

1. 1

   Confirm the result

   Make sure the test followed the checklist. A second short-term test, or two side by side, is how EPA's guides handle a quick decision.

2. 2

   Get more than one estimate

   EPA says to choose a mitigation contractor as you would for any home repair: get more than one estimate, and ask for and check references.

3. 3

   Read the contract

   EPA's Consumer's Guide says the contract should describe the work, the system and how it will operate, and state whether any warranties or guarantees are transferable if you sell your home.

4. 4

   Have the system installed to standard

   Any mitigation system must conform to your state's regulations. Where there are none, EPA recommends its most current voluntary consensus-based standards.

5. 5

   Retest independently

   Test again after the work to confirm the level has come down. EPA recommends an independent, qualified radon tester.

6. 6

   File the paperwork

   Keep the before and after results, the contract, the operating and maintenance instructions and any warranties for the buyer.

Choosing a mitigation contractor

EPA says a qualified mitigation contractor should review the measurement results before any work, give you a detailed written proposal, design and install the system to EPA's recommended standard or state and local codes, and make sure the finished system works. Radon411 lists mitigation professionals.

EPA also warns that a potential conflict of interest exists if the same person or firm performs the testing and installs the mitigation system. Some states may require a signed waiver in that case.

Should the seller pay for radon mitigation?

EPA does not say. It says that if elevated levels are found during the transaction, the buyer and seller should discuss the timing and costs of radon reduction, and that the contract can state when mitigation will be done and who will pay. What EPA does say is that fixing before listing gives you more time, and that most homes can be fixed for about the same cost as other common home repairs. See how mitigation cost works.

EPA's Consumer's Guide to Radon Reduction speaks to this directly: if you are selling a home that has a radon reduction system, inform potential buyers and supply them with information about the system's operation and maintenance.

Radon mitigation in a real estate listing

EPA says the results and records of a fix could be a positive selling point, and in its radon myths and facts it says the added protection will be a good selling point. Where radon problems have been fixed, EPA says, home sales have not been blocked. How you word a listing is up to you and your agent; what backs it up is the paperwork above.

EPA's Home Buyer's and Seller's Guide says the cost of making repairs to reduce radon levels depends on how your home was built and other factors, that most homes can be fixed for about the same cost as other common home repairs, and to check with and get an estimate from one or more qualified mitigators. The published figures are older or narrower than a quote, so they are shown with their dates.

Time is the seller's advantage. EPA says it is better to correct a radon problem before placing your home on the market because then you have more time to address it: time to get more than one estimate, to read the contract, and to retest before a buyer's inspection period starts. The mitigation cost page explains what drives a quote.

That line comes from a state radon program's homeowner page, and it matches what sellers can plan around: the work itself is short, while the estimates before it and the test after it take longer. EPA's guide says to test again after the radon mitigation work has been completed to confirm that previous elevated levels have been reduced, and recommends that the test be conducted by an independent, qualified radon tester. That result, with the date and the tester's name, is the document a buyer's agent will ask to see first.

EPA's Citizen's Guide says that during home sales, buyers often ask if a home has been tested, and if elevated levels were reduced. EPA's guide for buyers tells them what to find out before accepting a seller's test, which is the seller's checklist in reverse.

If the house has a radon-reduction system, EPA tells buyers to ask the seller for any information they have about the system, so the system's paperwork belongs in the same folder. A buyer may still ask for a new test; EPA lists the usual reasons, from an old test to a lower level they plan to use.

If your home was built with radon-resistant features, say so and show the result. EPA's guide tells buyers of a new home to ask if radon-resistant construction features were used and if the home has been tested. It says every new home should be tested for radon as soon as possible after occupancy, and if the result is 4 pCi/L or more, a vent fan can easily be added to the passive system to make it an active system.

A buyer will want a test result either way, because features reduce entry but do not measure it. More in passive radon systems.

A buyer may want their own result. EPA's Citizen's Guide says buyers frequently want tests made by someone who is not involved in the home sale. The test runs in your home, so your household's cooperation is part of the result; EPA says a qualified tester can emphasize to occupants that a reliable result depends on it.

• Keep all windows closed and doors closed except for normal entry and exit, and do not run fans or machines that bring in outside air. For a test of 2 to 4 days, start at least 12 hours before.
• Run heating and cooling normally. For a test of less than a week, use only air conditioners that recirculate indoor air.
• Do not disturb the test device at any time.
• Keep any radon-reduction system running for the whole test.

Preventing sellers from moving a radon test, and why it backfires

EPA lists how testers prevent or detect interference: devices that frequently record radon levels to catch unusual swings, motion detectors, proximity detectors, barometric pressure and temperature records, tamper-proof seals on windows, and a non-interference agreement signed by the seller or occupant.

Disclosure rules for radon vary by state, and Radon411 does not state any one state's rule here. EPA's guide describes a state or local government that requires disclosure of radon information to buyers as one reason a buyer may ask for a new test. Your state radon program is the place to start; find it in state radon programs.

Whatever your state requires, EPA's advice to sellers already points toward sharing: provide test results to the buyer, and save the information about any fix. The radon disclosure guide covers what to share, what buyers ask and how to find the rule that applies to you.