N.Y.C. Admin. Code § 28-309.4.2: § 28-309.4.2 Preservation of documents, inspection, and audit.

An owner of a covered building shall maintain such records as the department determines are necessary for carrying out the purposes of this article, including but not limited to energy and water bills and reports or forms received from utilities and tenants. Where energy use within separately metered tenant spaces is omitted, records shall be maintained documenting the owner's efforts to obtain such information. All records shall be preserved for a period of three years, provided that the commissioner may consent to their destruction within that period or may require that such records be preserved longer than such period. At the request of the department, such records shall be made available for inspection and audit by the department at the place of business of the owner or at the offices of the department during normal business hours.