No sign or other advertising structure shall be erected, relocated or maintained so as to prevent free ingress or egress, or block any light or ventilation openings. No sign of any kind shall be located or attached so as to obstruct emergency facilities or equipment. No sign, otherwise permitted in this Chapter, supported by or suspended from a building shall hang less than eight (8) feet above a pedestrian path, or less than fifteen (15) feet above a vehicular path.