N.Y.C. Admin. Code tit. 26, ch. 4 § 26-515

a. An owner seeking to recover possession pursuant to subparagraph (c) of paragraph nine of subdivision c of section 26-511 of this chapter shall notify the tenant in occupancy not more than one hundred fifty and not less than one hundred twenty days prior to the end of the tenant's lease term, by mail, of such owner's intention not to renew such lease in order to recover the dwelling unit for its charitable or educational purposes. The owner may give such notice within one hundred twenty days of the expiration of the tenant's lease term, provided it may not commence a summary proceeding to recover the dwelling unit until the expiration of one hundred twenty days from the giving of such notice and, provided, further, that the tenant may remain in occupancy until the commencement of such proceeding at the same rent and upon the same terms and conditions as were provided in his or her expired lease. The notice of intention not to renew the tenant's lease shall be accompanied by a notice on a form prescribed by the division of housing and community renewal setting forth the penalties to which an owner may be subject for his or her failure to utilize the tenant's dwelling unit for the charitable or educational purpose for which recovery of the dwelling unit is sought.


b. If any owner who recovers a dwelling unit pursuant to such subparagraph (c), or any successor in interest, utilizes such unit for purposes other than those permitted under such subparagraph, then such owner or successor shall, unless for good cause shown, be liable to the removed tenant for three times the damages sustained on account of such removal plus reasonable attorney's fees and costs as determined by the court, provided that such tenant commences such action within three years from the date of recovery of the unit. The damages sustained by such tenant shall be the difference between the rent paid by such tenant for the recovered dwelling unit, and the rental value of a comparable rent regulated dwelling unit on the open market. In addition to any other damage, the reasonable cost of removal of the tenant's property shall be a lawful measure of damages.


c. Where a dwelling unit has been recovered pursuant to such subparagraph (c) and within four years of such recovery is rented to a person or entity for purposes other than those permitted pursuant to such subparagraph (c), unless for good cause shown, the rent charged by such owner or any successor in interest for four years following such recovery shall not exceed the last regulated rent payable prior to such recovery.


d. If the owner is found by the commissioner, to have recovered possession of a dwelling unit pursuant to such subparagraph (c) and within four years of such recovery such owner or any successor in interest shall have utilized such unit for purposes other than those permitted pursuant to such subparagraph (c), unless for good cause shown, the commissioner shall impose upon such owner or successor in interest, by administrative order after hearing, a civil penalty for any such violation. Such penalty shall be in an amount of up to one thousand dollars for each offense. Such order shall be deemed a final determination for the purposes of judicial review. Such penalty may, upon the expiration of the period for seeking review pursuant to article seventy-eight of the civil practice law and rules, be docketed and enforced in the manner of a judgment of the supreme court.