Sky lobby

This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (February 2008)

The former World Trade Center's twin towers used sky lobbies, located on the 44th and 78th floors of each tower.

A sky lobby is an intermediate floor where people can change from an express elevator that only stops at the sky lobby to a local elevator which stops at every floor within a segment of the building. When designing very tall (supertall) buildings supplying enough elevators is a problem - travellers wanting to reach a specific higher floor may conceivably have to stop at a very large number of other floors on the way up to let other passengers off and on. This increases travel time, and indirectly requires many more elevator shafts to still allow acceptable travel times - thus reducing effective floor space on each floor for all levels.

The sky lobby was invented to resolve this issue and first used in the John Hancock Center in Chicago.^[1]

John Hancock Center

The John Hancock Center's sky lobby on the 44th floor serves only the residential portion of the building that occupies floors 45-92. Three express elevators run from the residential lobby on the ground floor to the 44th floor, with two of the elevators stopping at the parking garage's main level on floor 6. At floor 44, residents transfer to two banks of three elevators. One bank serves floors 45-65 and the other serves 65-92. Although all six elevators stop at floor 65, this floor is roughly the same layout as the residential floors immediately above and below it. It is not a sky lobby because residents can also board elevators to higher floors at floor 44.

The Hancock's 44th floor sky lobby includes a pool, gym, dry cleaner, convenience store, about 700 mailboxes, two "party" rooms, a sitting area overlooking Lake Michigan, a small library, a refuse room (with trash chutes emptying here), offices for the managers of the residential condominium,^[2] and a polling station for residents during elections.

Floors above 92 are serviced by direct passenger elevators from the ground floor, an emergency elevator from the ground floor, and by two freight elevators that run from floors 44 to 98.

Buildings with sky lobbies

(in chronological order by construction date)

• John Hancock Center (Sky lobby at 44th floor) in Chicago, Illinois, United States
• 1 World Trade Center (Contained two sky lobbies at 44th and 78th floors) in New York City, New York, United States
• 2 World Trade Center (Contained two sky lobbies at 44th and 78th floors) in New York City, New York, United States
• Willis Tower (Two double level sky lobbies at 33rd/34th and 66th/67th floors) in Chicago, Illinois, United States
• Columbia Center (Sky lobby at 40th floor with a Starbucks) in Seattle, Washington, USA
• Seattle Municipal Tower (Sky lobby at 40th floor) in Seattle, Washington, USA
• Izumi Garden Tower in Tokyo, Japan
• Petronas Twin Towers in Kuala Lumpur, Malaysia located at level 47/48
• Taipei 101 (Two double level sky lobbies at 35th/36th and 59th/60th floors) in Taipei, Taiwan
• The Shin Kong Life Tower in Taipei has a sky lobby on floor 16, above the department store.
• Immigration Tower, Wan Chai North, Hong Kong Island, Hong Kong
• Central Plaza, Wan Chai North, Hong Kong Island, Hong Kong

References