Many of the radon levels in Carlisle are high. This is not unusual. There is a great locally based company, Storch Radon 800-362-6290 that installs radon mitigation systems very reasonably...most $1000 and they guarantee the level of re-testing to be under 4 after they install. I would highly suggest this. You could maybe also use that high radon to your advantage and ask for some credit from the sellers?

There is a process for the treatment of radon including venting and the cost should be included as part of the P&S or it should be handled by the seller prior to closing!

In addition to all excellent answers below yes unfortunately it might affect the resale value of your home. Buyers do get reluctant to buy a home with a Radon Mitigation system.
We do our best to educate the buyer by explaining to them why radon is in the basement especially in the new construction, but they still get spooked.
Definitely listen to other advice and have the seller install the mitigation system before you move/buy.

Did you discuss this with your inspector and agent what were there comments?
http://www.lynn911.com

Good morning Ibeliza:

Left unchecked Radon can be a serious issue. The good news is that a Radon mitigation system is relatively inexpensive to have installed and that the system will mitigate the issue. Regarding resale, I am finding that Radon mitigation systems are more widely accepted, especially where new homes (because of how tight they are built) are requiring them more and more.

Good luck,

Rob

Ibeliza,
Radon levels above the EPA action level of 4.0 pCi/L are not terribly uncommon here in Massachusetts. I've had tests come back more than 50x that level and we were able to correct the problem. The sellers should install a radon mitigation system before you buy. As long as the sellers install a mitigation system that keeps the radon level below 4.0 you should have no problems with the price of your house moving forward (at least not due to any radon issues...). As long as the radon levels are kept in check (< 4.0 PCi/L) with a properly working mitigation system, it should be a non-issue for future potential buyers. I put a link to the AccuStar Labs website below which has some great radon info for homeowners.

Congratulations (almost) on your new home in Carlisle! It's a lovely community.