21 GCA § 61402: Buildings and Structures Permitted Above Height Limit.

The following buildings, structures and equipment may be erected and maintained above the permitted height limit:

(a) In the A Zone, any building may exceed the height limit of two stories or thirty (30) feet, if such building is located at least at a distance equal to two times the height of the building from any lot line;

(b) Shelters accessory to roof gardens or decks, providing such shelters are open on two or more sides, occupy less than half the roof area, do not exceed the height limit by more than ten (10) feet, and are set back at least eight (8) feet from each lot line;

(c) Roof structures for the housing of stairways, tanks, ventilating fans, or similar structures and equipment for the maintenance of the building; and

(d) Aerials, flagpoles, skylights, steeples, towers, fire or parapet walls, or other similar structures.

(e) Hotels, provided, that for every foot in elevation exceeding the standard limitation, two feet shall be added to each of the required yard depths and widths; and provided, further, that the height limit for any such hotel shall be six (6) stories (the six (6) stories shall not exceed a height of seventy-five (75) feet).