Cost-Benefit Analysis
What is the best predictor that a home will have elevated radon levels? (in the Twin Cities, the threshold for remediation is 
above 4.0 PicoLiters per million parts).
One or more other homes on the block have elevated radon levels.
One of the benefits of being a more experienced Realtor is, having done deals all over town, I know which neighborhoods and even blocks are at higher risk.
Radon Risk
Why recommend that home buyers test for radon — my routine practice for the last two-plus years?
Because it passes the cost-benefit test.
Easily.
Assuming that radon remediation costs about $1,500 for the average home, a radon test costs $150, and the odds of finding radon are between 1-in-3 and 50%, statistically, the “benefit” is $625 vs. a cost of $150.
Any time a benefit is more than 4x the cost . . . you do it.
Home Seller Push-Back
Now that radon tests are becoming more prevalent, home Sellers are becoming more sophisticated about challenging them.
So, I had a deal earlier this year where the home seller protested that the results were invalid because the testing device was placed on the floor, rather than 2′ above it as required.
What happened next?
The Buyer and Seller agreed to extend the Inspection period, the home inspector re-tested for radon . . . and the results came back identical to the first test.
Bottom line: the Seller and Buyer agreed to discount the sales price so the Buyer could remediate, post-closing.
