Unless a maximum height regulation is stated in § 27-305, Use Regulations, for a specific use, no principal building or structure shall exceed 35 feet and 2 1/2 stories in height. Any building or structure accessory to a dwelling, which building or structure is located at the setback line applicable in the underlying zoning district, shall be limited to 14 feet in height, however, the height may be increased one foot for every two additional feet the building or structure is situated away from the applicable setback line to a maximum of 25 feet in height. For exceptions, refer to Uses A1(3) [§ 27-305, Subsection 1, Use A1(3)], A3(5) [§ 27-305, Subsection 1, Use A1(3)], I6(2)(C) [§ 27-305, Subsection 9, Use I6(2)(C)], I8(3) [§ 27-305, Subsection 9, Use I8(3)] and § 27-1910.