Nothing in this title shall require any change in the plans, construction, alteration or designated use of a structure for which construction has commenced prior to the adoption of this title, except that if the designated use will be a nonconforming use, it shall, for the purpose of section 6-6-9-4 of this chapter, be a discontinued use if not in operation within three (3) years of the date of issuance of the building permit. (Ord. 86, 12-7-1993)