All applications for the use of streets or other public spaces of the City for the purpose of depositing building materials thereon shall be made to the City Engineer describing the grounds and the desired periods of occupation. Permits for the use of streets and other public places for the deposit of building materials shall not be granted, in the first instance, for a longer time than four months, but may be renewed from time to time at the discretion of the City Engineer for not more than one month at any one time. The permit shall not authorize the preparation in the streets or places belonging to the City of materials which can be prepared elsewhere, nor does it authorize the deposit of materials in or over the gutter so as to prevent a free passage of water, nor to extend beyond the middle of the street. The permit shall specify the grounds to be occupied which must be in front of the premises to be built upon unless more space is absolutely necessary.