Most everyone has heard of radon, which is an odorless invisible gas that naturally occurs throughout the subsurface of the earth and is found across the United States.  As radon gas moves up through the soil, it can be drawn into buildings because of the difference in air pressures.  The air pressure inside your home is usually lower than the pressure in the soil around the foundations of buildings.  Because radon is a cancer causing radioactive gas it is important to be aware of it and to take precautionary measures when building a home.  At Fine Line Homes we use a combination of the placement of an appropriate vapor barrier and install perforated pipe under the basement floor which is vented through the roof of the house.  This offers a practical passive radon reduction system.  If at any time after the home is occupied radon levels are found to be elevated, the passive system can easily be converted to an active system by installing a fan unit in the attic on the vent pipe.  The fan can be energized by tapping the circuit for the attic light.  No need for retrofits or vent pipes attached to the exterior of the house.