Nothing contained in these provisions shall require any change in the plans construction, alteration, or designated use of a structure for which a building permit has been issued and construction work has commenced prior to the adoption of these provisions; except that, if the designated use will be nonconforming, it shall, for the purposes of Section 640.050, be a discontinued use if not in operation within two years of the date of issuance of the building permit. (Ord. 13-2010)