An accessory building is a detached subordinate building, any part of which is within a required minimum yard of the subject Zoning District, and the use of which is incidental to that of the main building on the same lot, or to the use of the land. For properties within a Residential zone, or with a Residential use, the use of such accessory buildings are restricted to garages, carports, storage sheds, and similar buildings which are found by the Building Official to conform to the "U" (utility) occupancy classification.