Sky lobby

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. The sky lobby, first used in the John Hancock Center in Chicago, [cite web
url=http://www.otis.com/otis150/section/1,2344,ARC3066_CLI1_RES1_SEC5,00.html
publisher=Otis Elevator Company
title= Otis History: The World Trade Center
accessdate=2006-12-07] is one approach to the problem, because travellers to specific floors do not tie up the main elevator due to getting on and off, increasing the efficiency of the 'long-distance' elevators, and reducing the number of elevator shafts at a given point.

Example: 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, [cite web
url=http://members.aol.com/earlrealtr/common.htm
publisher= Earl Reid
title= The John Hancock Center
accessdate=2008-01-07] 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 in Chicago, Illinois, United States
*1 World Trade Center (Two sky lobbies at 44th and 78th floors) in New York City, New York, United States
*2 World Trade Center (Two sky lobbies at 44th and 78th floors) in New York City, New York, United States
*Sears 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, ROC
* 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