Yes. Your home can have high radon levels whether it is old or new, well-sealed or drafty, and with or without a basement. Every new home should be tested after occupancy, even if it was built radon-resistant. If radon levels are still in excess of 4 pCi/L, the passive system should be activated by having a qualified mitigator install a vent fan.
New homes are often built with radon-resistant features. Radon-resistant construction techniques can be effective in preventing radon entry. When installed properly and completely, these simple and inexpensive techniques can help reduce indoor radon levels in homes. In addition, installing them at the time of construction makes it easier and less expensive to reduce radon levels further if these passive techniques don’t reduce radon levels to below 4 pCi/L.