Since 2015, new one- and two-family homes and townhouses in Worcester, Essex, and Middlesex Counties are required to have a passive radon system installed when they are built.
These three counties are named in the International Residential Code Appendix F which was incorporated into the Massachusetts Building Code as areas that have high radon potential (Table AF101(1) High Radon Potential (Zone 1) Counties).
To find out what county your town is in, click this link: https://www.sec.state.ma.us/cis/cisctlist/ctlistcoun.htm.
If you live in a subdivision of a town, consult here to check which town your subdivision is located in: https://www.sec.state.ma.us/cis/cisuno/unoidx.htm
Jefferson, MA is in Holden, MA which is in Worcester County
Hyde Park, MA is in Boston, MA which is in Suffolk County
Hyannis, MA is in Barnstable, MA which is in Barnstable County
Requirements for installation of passive radon systems can be found at this link: https://www.mass.gov/doc/appendix-f-passive-radon-gas-controls
According to the Massachusetts Building Code, installation of a passive radon system as detailed in the ANSI/AARST Standard may be substituted for Appendix F Guidance. A number of the ANSI/AARST construction standards are available for viewing and/or purchase at: https://standards.aarst.org