New Jersey Statutes Title 40A. Municipalities and Counties 40A § 21-7

If the ordinance adopted pursuant to this act shall provide for the exemption from taxation of improvements to commercial or industrial structures, it shall require that, in determining the value of real property, the municipality shall regard up to the assessor's full and true value of the improvements as not increasing the value of the property for a period of five years, notwithstanding that the value of the property to which the improvements are made is increased thereby. During the exemption period, the assessment on the property shall not be less than the assessment thereon existing immediately prior to the improvements, unless there is damage to the structure through action of the elements sufficient to warrant a reduction.

The ordinance may: a. grant exemptions for all commercial and industrial improvements; b. define categories of improvements which shall be approved by the assessor upon proper application, and other categories of improvements which may be exempted only after review, evaluation and approval by the municipal governing body; or, c. authorize exemption for improvements on an individual basis after review, evaluation and approval of each application by the governing body.