The Commissioner of Building and Zoning Inspection or any of his designated agents, may at any reasonable hour, enter any dwelling, multifamily dwelling, building, structure or premises within the City to perform any duty imposed on him by this Building Code, provided that permission to enter is obtained from the occupant or, in the case of unoccupied property, from the owner or his agent. If such permission is refused or is otherwise unobtainable, a search warrant must be obtained before such entry or inspection is made, except in the case of an existing emergency in which case entry may be made at any time and no search warrant is necessary. No person shall refuse to permit such emergency entry or inspection, nor shall any person hinder, obstruct, resist or abuse any person making or attempting to make such entry or inspection.