N.Y.C. Admin. Code § 27-346: § 27-346 Partitions and furring.

In buildings of construction group I, partitions and furring shall be constructed of noncombustible materials, except that nonbearing partitions that are not required to have a fire-resistance rating, and furring may be constructed of fire retardant treated wood as provided in subdivision (d) of section 27-328 of article three of this subchapter, and except that such partitions and furring, may be constructed of combustible materials in spaces classified in occupancy group E, J-2, or J-3, provided the following conditions are met:

(a) the space containing the combustible partitions does not exceed five thousand square feet in area within a noncombustible enclosure having a fire-resistance rating of at least one hour.

(b) the space is in a single tenancy.

(c) glass or slow burning plastic is used for glazing.