No person shall construct or erect or cause to be constructed or erected, in, under or upon any street, alley or sidewalk in the City, any area, cellarway or step, without first obtaining the consent of the Director of Public Works. No person owning, using or occupying any such cellarway or area having an entrance upon any street, alley or sidewalk in the City, shall allow such entrance to remain uncovered or unsecured by a safe and sufficient door or grating covering the whole opening into such street, alley or sidewalk, nor shall such person allow the door or other covering to remain open except when in actual use. The Director of Public Works shall not grant permission for the permanent occupancy for private use of any part of any street, alley, sidewalk or public place in the City, nor shall he grant permission for any use thereof for private purposes which may obstruct the free use thereof by the public. (1947 Code §25.15)