Sky lobby

The sky lobby in Central Plaza, Hong Kong

A sky lobby is an intermediate interchange floor where people can change from an express elevator that stops only 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 other main technique to increase usage without adding more elevator shafts is double-deck elevators.

Early uses of the sky lobby include the original Twin Towers of the World Trade Center and 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, by an emergency elevator from the ground floor, and by two freight elevators that run from floors 44 to 98.

Buildings with sky lobbies

The former World Trade Center, designed by Minoru Yamasaki, used sky lobbies, located on the 44th and 78th floors of each tower.

View from the sky lobby in the JPMorgan Chase Tower, Houston

The Nina Tower sky lobby

Building Name	Year	Location	Floors of sky lobby(s)
John Hancock Center	1969	Chicago, Illinois, United States	44
One World Trade Center	1972	New York City, New York, United States	44, 78
Two World Trade Center	1973	New York City, New York, United States	44, 78
Willis Tower	1973	Chicago, Illinois, United States	33/34, 66/67
NatWest Tower	1980	London, United Kingdom	23/24
JPMorgan Chase Tower (Houston)	1982	Houston, Texas, United States	60
Wells Fargo Plaza (Houston)	1983	Houston, Texas, United States	34/35, 58/59
Williams Tower	1983	Houston, Texas, United States	51
Columbia Center	1985	Seattle, Washington, United States	40
Miami Tower	1987	Miami, Florida, United States	11
Seattle Municipal Tower	1990	Seattle, Washington, United States	40
Petronas Twin Towers	1999	Kuala Lumpur, Malaysia	41/42
Izumi Garden Tower	2002	Tokyo, Japan	–
First World Hotel	2008	Genting Highlands, Pahang, Malaysia	3, 8
Taipei 101	2004	Taipei, Taiwan	35/36, 59/60
Shin Kong Life Tower	1993	Taipei, Taiwan	16
Revenue Tower	1990	Wan Chai, Hong Kong	–
Immigration Tower	1990	Wan Chai, Hong Kong	–
Central Plaza	1992	Wan Chai, Hong Kong	–
The Center	1998	Central, Hong Kong	42
Two International Finance Centre	2003	Central, Hong Kong	33, 35, 55, 56
Bloomberg Tower	2004	New York City, New York, United States	6, 20
Nina Tower	2006	Tsuen Wan, New Territories, Hong Kong	41
One Island East	2005	Quarry Bay, Hong Kong	–
The Bow	2007	Calgary, Alberta, Canada	18, 36, 58
Shanghai World Financial Center	2008	Shanghai, China	28/29, 52/53
Burj Khalifa	2010	Dubai, United Arab Emirates	43, 76, 123
200 West Street	2009	New York City, New York, United States	11
International Commerce Centre	2010	Central, Hong Kong	48/49, 98/99
Jeddah Tower	2018	Jeddah, Saudi Arabia	– [3]
One World Trade Center	2014	New York City, New York, United States	64
Rosslyn Central Place Office Tower	2016	Arlington, Virginia, United States	6
Australia 108	2019	Melbourne, Australia	83,84[4][5]
Wilshire Grand Tower	2017	Los Angeles, California, United States	70
Shanghai Tower	2015	Shanghai, China	22–23, 37–38, 52–53, 68–69, 101
Tokyo Sky Tree	2012	Sumida, Tokyo, Japan	4F, 350m
Wisma 46	1996	Jakarta, Indonesia	46
UOB Plaza Tower One	1995	Singapore, Singapore	37–38
S2 Building EEPIS	2015	Surabaya, Indonesia	1[6]
Darmo Trade Center Wonokromo	2004/2005	Wonokromo, Surabaya, Indonesia	1[7]
Abraj Al-Bait Clock Tower	2012	Makkah, Saudi Arabia	M2,[8] M4[9]
Plaza Tunjungan 5	2015	Surabaya, Indonesia	20

References

1. "Otis History: The World Trade Center". Otis Elevator Company. Archived from the original on 2006-11-15. Retrieved 2006-12-07.
2. "The John Hancock Center". Earl Reid. Retrieved 2008-01-07.
3. "Adrian Smith interview". WTTW. August 4, 2011. Retrieved 2011-08-07.
4. "Six Star Hotel – Australia 108". Retrieved 2013-03-19.
5. "Rising high: 108-storey super tower planned for Melbourne". The West Australian. 2012-11-12. Retrieved 2013-03-19.
6. This is not a ground floor, and in other building on EEPIS complex, this floor is known as 2nd floor.
7. This is not a ground floor, and the clearance between this floor and ground level is higher than roof of some building surrounding the mall
8. Used as the hotel lobby
9. Used as the serviced apartments lobby