In the CG zone, the height of every building or structure hereinafter designed, erected, or structurally altered or enlarged shall be regulated by conformance to the requirements of the most recent edition of the International Building Code as adopted by action of the Municipal Council. After the effective date of this Chapter (December 12, 1974), all new structures exceeding two (2) stories in height shall be served with elevators or escalators in addition to the stairways otherwise required by law.