The best way to address radon (both from an aesthetic and cost-efficient perspective) is to integrate it into a home when its being built. Typically, the slab foundation is poured on a 4-inch, porous, gravel medium. A vapor barrier is placed over the gravel to inhibit the intrusion of moisture through the concrete. A 3-4 inch PVC pipe (Schedule 40) is mounted into the gravel and is run up through the house (usually hidden in walls) and proceeds up into the attic and through the roof. If the home is later tested for radon and the levels are found to be elevated, a fan can be installed on the pipe in the attic that will create a negative pressure under the slab foundation (or under the plastic membrane put down and "sealed" in the crawl space) and will cause the radon gases to be "sucked out of the home" and vented harmlessly into the earth's atmosphere before it has a chance to get inside.
The EPA recommends the installation of passive systems in all new construction. By doing so at the time of construction you can be sure that radon will no be a significant concern in the future and it will make it much more cost-effective for the home owner to later address. There is a national trend to require that "passive piping" is installed in new homes when they are built as a part of the county building code. In South Carolina, Greenville County is the ONLY county to date which has implemented this requirement (since 1998).
Several National Green building programs have seen the benefits of integrating passive radon piping into their homes and offer "points" to participants for their inclusion. (Energy Star, EarthCraft, National Association of Home Builders).
Homeowners need to understand that having "passive systems" installed in homes DOES NOT guarantee you won't have problem with radon, it's presence will simply make it easier (and less expensive) to fix! You don't have to be an a RNNC county to have radon piping installed when your house is built. Simply ask your builder. But its important to get your home tested AFTER its completed to make sure that your levels are low. We frequently work with builders to make sure the passive piping systems are installed correctly according to EPA installation procedures.