Neb. Rev. Stat. § 17-550: Neb. Rev. Stat. § 17-550

Cities of the second class and villages shall have power to prescribe and alter limits within which no buildings shall be constructed except of brick, stone, or other incombustible material, with fireproof roof. After such limits are established, no special permits shall be given for the erection of buildings of combustible material within such limits.