Use of 222Rn-resistant techniques in new home construction

The objective of this project was to assess the status of the use of 222Rn-resistant construction techniques in new home construction in the eight Zone 1 counties of North Carolina. Zone 1 counties have an average predicted indoor 222Rn screening potential greater than 148 Bq m(-3)(4 pCi L(-1)). To facilitate a response from builders, a brief survey form was designed and printed on the back of a self-addressed, postage-paid postcard. This survey form was mailed to 460 home builders in the Zone 1 counties. The response rate was 17%, which can be compared to the 4.9% response rate obtained in a national survey conducted by the National Association of Home Builders Research Center. In our survey, 62% of the responding builders reported that they had built some or many homes in 1996 "using construction techniques to reduce the entry of radon into homes," but only 10% of the builders reported using these techniques for many homes. The National Association of Home Builders survey determined that, nationally, 30% of homes built in Zone 1 counties had 222Rn venting features. There is the potential for bias in the results of our survey (as well as in the results of the National Association of Home Builders survey) since the response rates were low.