Connecticut radon requirements for new construction
2022 CT State Building Code, Appendix AF
What your permit set must show
- Connecticut adopted 2021 IRC Appendix AF ("Passive Radon Gas Controls") into the 2022 CT State Building Code, applying it statewide to all new detached one- and two-family dwellings and townhouses.
- The requirement was originally adopted as Appendix F in the 2016 CT code and carried forward under the current Appendix AF numbering in the 2022 code cycle.
- Appendix AF carries the same substantive rough-in components as the current Appendix BE numbering: sub-slab depressurization piping, a sealed soil-gas barrier, and sealed floor penetrations.
Common questions
Does every new Connecticut home need a radon rough-in?
Yes, for detached one- and two-family dwellings and townhouses. The 2022 CT State Building Code incorporates 2021 IRC Appendix AF statewide, with no county-level exemption.
Why does Connecticut cite Appendix AF instead of Appendix F or BE?
Connecticut's current code cycle (2022) uses the 2021 IRC edition's numbering, Appendix AF. The requirement was originally adopted as Appendix F in the 2016 CT code and carries the same substantive provisions under the newer number.
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