Any lawfully existing use that, at the time of its establishment, was not classified as a conditional use, but which now, because of the passage of this Development Code, or amendment thereto, is listed as a conditional use in the district in which it is located, shall be deemed without further action to be a conditional use. Any change, modification, enlargement or alteration of such use, site development conditions or signs, or change in operations shall only be permitted upon review and approval by the Planning Commission according to the procedures for conditional uses set forth in Chapter 1131.