Effective date; effect on prior permits. This
chapter shall take effect upon its final passage and publication as
provided by law, but any building or structure, the erection of which
has been authorized by a permit issued by the Construction Official
prior to the passage of this chapter, may be completed in accordance
with the permit and the requirements of law and ordinances in force
at the time when such permit was granted and may be used for the purpose
designated in the plan and in the permit.