Other buildings and structures shall not exceed the maximum height limitations of the zoning district in which they are located; provided, however, that structures appurtenant to nonresidential buildings, including, but not limited to, parapet walls, chimneys, cooling towers, elevator bulkheads, fire towers, stacks, elevated water towers, stage towers, scenery lofts, monuments, cupolas, domes, spires, penthouses housing necessary mechanical appurtenances, and HVAC or similar equipment on the roof of the building may exceed the district height limitations if approved by the Planning Commission in site plan review.