The NJ Department of Community Affairs formally adopted the 2018 IECC and 2018 IRC for residential buildings.
According to NJ DCA: "For a period of six months following the operative date of a subcode revision, applicants may submit a complete permit application, including all prior approvals, to be reviewed under the code in force immediately preceeding the subcode revision. Provided that the application is complete, the construction official and applicable subcode officials shall perform the plan review and issue construction permit(s) based on the code in force immediately prior to the operative date of the subcode revision. This grace period shall apply only to revisions of subcodes."
Therefore, from 9/3/19 to 3/3/2020, builders can submit permits using either the 2015 or 2018 IECC/IRC.
All permit applications submitted as of this date must comply with the 2018 IECC/IRC.