After the effective date of this Ordinance any use established or changed to, and any building, structure or tract of land developed, constructed or used for, any permitted or permissible principal or accessory use in the I 1 or I 2 zones shall comply with all of the performance standards herein set forth in the district involved. If any existing use of any building or other structure is extended, enlarged, or reconstructed, the performance standards for the district involved shall apply with respect to such extended, enlarged or reconstructed portion or portions of such use of any building or other structure.