I bet you many building construction professionals do not know the meaning and correct usage of terms. Let's once again visit the National Building Code. 2.1 ACCESSORY STRUCTURE: Shall mean a building or structure, the use of which is incidental to that of te main building and which is located on the same plot. 2.2 AGRICULTURAL BUILDING: Shall mean a structure designed and constructed to house farm implements, hay, grain, poultry, livestock or other horticultural products. This structure shall not be a place of human habitation or a place of employment where agricultural products are processed, treated or packaged, nor shall it be a place used by the public. 2.3 AIRPLANE HANGAR (PRIVATE): Shall mean a building for the storage of four or less single engine aircraft in which volatile or flammable oil is not handled, stored or kept other than that contained in the fuel storage tank of the plane. 2.4 AIRPLANE HANGAR (PUBLIC): Shall mean a building for the storage, care and/or repai...