Permits shall be obtained at least two working days before the work is commenced, and shall not be transferred or assigned except as provided herein. The Director of Public Works shall examine each application to determine if it complies with the provisions of this title and may inspect the premises which are desired to be used in order to ascertain any facts which may aid in determining whether a permit shall be granted. If the Director of Public Works finds that the application conforms to the requirements of this title pertaining thereto, and also that the proposed use of such public place will not unduly interfere with the rights of the public, he may approve the application. If the application is approved, the Director of Public Works shall issue a permit, upon the applicant's compliance as herein specified with the provisions of this title relative to bond and indemnity. The permit shall provide a time limit within which the work shall be completed, and work shall commence within ten days after application is approved. Unless an extension of time is granted by the Director of Public Works, the permit shall be void if the work is not commenced and completed within the dates stated.