Bought a kit from amazon with my neighbour. Our house was in the normal range (9 yr old house in Aspen). I understand that radon can seep in if there's cracks in foundation and something I plan to do maybe every 5 or so years. Might be over kill but for some piece of mind, I figure it's worth the $100 or so - esp. since my kids spend a ton of time in the basement now.