Only accessory storage buildings defined in this chapter are permitted as accessory storage containers on property in any residential zone of the city, or on any property within the city where the primary use is residential. Cargo containers, railroad cars, truck vans, converted mobile homes, travel trailers, recreational vehicles, bus bodies, vehicles, and similar prefabricated items and structures originally built for purposes other than the storage of goods and materials are not considered to be accessory structures or buildings.