N.J. Stat. § 54:4-23a
Any other law to the contrary notwithstanding, no building or other structure newly constructed on any parcel of real property and intended for occupancy and use for residential purposes as a single family dwelling shall be added to the assessment list as real property subject to taxation, until a certificate of occupancy or temporary certificate of occupancy has been issued and unless the building or other structure is actually occupied and used for such purposes; provided, however, that such building or structure shall be omitted from taxation for a period not to exceed 24 months. At the termination of the 24 month period or following the granting of a certificate of occupancy or temporary certificate of occupancy and the occupation and use of the building for residential purposes, the building or structure shall be assessed and taxed as of the first day of the month following the date of such use for the proportionate part of said year then remaining.
For the purposes of this act, "newly constructed" refers to construction which commenced on or after December 29, 1982. Construction will be deemed to commence on the date of the footing inspection. Nothing in this act shall be construed as applicable to any addition to, or improvement or alteration of, any existing building or structure.
N.J.S. § 54:4-23a