The goal of this project was to assess the joint influence of home construction and environmental (soil) characteristics in predicting radon concentration in homes. The first part of this work found the relationship between radon concentration and home construction factors was dependent on location of the radon test in homes. In basements, wall construction and degree of energy efficiency predominated in predicting radon concentration. On upper floors, age of home predominated in predicting radon concentration, with a general decrease in radon concentration with age of home. The second part of the study found texture of the soil on which the home is located was the most important predictor of radon concentration for homes tested in the basements. Precipitation totals in the year preceding the screening test were negatively correlated with radon concentration in homes, but the relationship was only apparent when basement wall type and soil texture was accounted for.