N.Y.C. Admin. Code § 4-110: § 4-110 School lands; sale of, at auction.

The board of estimate is authorized, upon the application of the board of education duly authorized and certified, to sell at public auction at such times and on such terms as they may deem most advantageous for the public interest, any land or lands and the buildings thereon, owned by the city, occupied or reserved for school purposes, and no longer required therefor. No property, however, shall be disposed of for a less sum than the same may be appraised by the board of estimate, or a majority of them, at a meeting to be held and on an appraisement made within two months prior to the date of the sale. At least thirty days notice of such sale, including a description of the property to be sold, shall be published in the City Record.