(a) Enclosed Buildings. All businesses, services or processing shall be conducted wholly within a completely enclosed building, except for the sale of automobile fuel, lubricants and fluids at service stations, loading and unloading operations, parking, the outdoor display or storage of vehicles, materials and equipment and the uses specified in Section 1151.01
(d).
(b) Night Operation. No building customarily used for night operation, such as a bakery or milk bottling and distribution station, shall have any opening, other than stationary windows or required fire exits, within 100 feet of any R District, and any space used for loading or unloading commercial vehicles in connection with such an operation shall not be within 100 feet of any R District.