It shall be unlawful for any person to construct any sidewalk, gutter or curb of cement or concrete within the City unless the grade of such sidewalk, gutter or curb has been established by the Street Transportation Director. It shall be the duty of the Street Transportation Director, upon demand being made in writing by all the owners of property fronting on any one block, to furnish the grades for any such sidewalks, gutters or curb within thirty days after such demand in writing. (Code 1962, § 35-62; Ord. No. G-3313, § 1)