780 CMR Section AF101.1 states that "This appendix contains minimum passive radon control requirements for all new construction. . .". Neither the International Building Code (IBC) nor the International Residential Code (IRC), or Massachusetts amendments thereto, provide a definition for new construction.
Some have questioned whether or not an addition to an existing building constitutes new construction; therefore requiring radon control methods to be incorporated into the addition. During their September, 2017 meeting, members of the Board of Building Regulations and Standards (BBRS) determined that the answer to this question is no; radon control methods are not required for the addition or existing portion of the building. Radon control is only required for ground-up, new construction in areas of high radon concentration as established by Appendix F and accompanying Radon Zone Map.