30 St Mary Axe On the building's top level (the 40th floor), there is a bar for tenants and their guests, with a panoramic view of London. A restaurant operates on the 39th floor, and private dining rooms on the 38th. Most buildings have extensive lift equipment on the roof of the building, but this was not possible for the Gherkin, since a bar had been planned for the 40th floor. The architects dealt with this by having the main lift only reach the 34th floor, and also a push-from-below lift to the 39th floor. There is a marble stairwell and a disabled persons'
30 St Mary Axe of the building during the summer and warm the building in the winter using passive solar heating. The shafts also allow sunlight to pass through the building, making the work environment more pleasing, and keeping the lighting costs down. The primary methods for controlling wind-excited sways are to increase the stiffness, or increase damping with tuned/active mass dampers. To a design by Arup, its fully triangulated perimeter structure makes the building rigid enough without any extra reinforcements. Despite its overall curved glass shape, there is only one piece of curved glass on the building, the lens-shaped cap at the apex.