Agricultural buildings, on lots of at least 10 acres, such as barns, silos, bins, sheds, and farm machinery sheds in the A-1, A-2, A-3 and A-4 agricultural districts shall not be considered accessory buildings. Such buildings are principal agricultural buildings and shall comply with the yard and height requirement of the agricultural districts.

Buildings on nonconforming lots in the A-1, A-2, A-3, or A-4 districts less than 10 acres shall be considered accessory buildings and shall comply with the provisions of this section. [Code § 12.18.4-4.]