Glass Tower

The Glass Tower is a fictional skyscraper featured in the 1974 Irwin Allen disaster film The Towering Inferno. The tower is 138 stories tall and sheathed with large floor-to-ceiling gold-tinted windows; exterior columns are clad in gold-colored metal panels. The lobby includes a large 16-story-high atrium (filmed at San Francisco's Hyatt Regency Embarcadero). There are offices up to the 80th floor. Floors 81 to 120 are purely residential. It is never stated what the purpose of floors 121 to 134 are, but the 135th floor features the 300 person capacity Promenade Deck ballroom, which affords an unparalleled view of San Francisco from a height of no less than 1500 feet (approximately 457 meters). This floor is serviced by two internal express elevators and 3 glass scenic elevators (although only one was functional at the time of the building's dedication). Floors 136 to 138 consist of machine rooms for the elevators and six massive water tanks which together hold one million gallons of water. The flat roof has a helipad.

Ultimate height of the building would vary depending on the height of the floors. If the view from the 135th floor is at 1500 feet (the approximate vantage point of the cyclorama created for the set of the Promenade Deck), then the total building height would be approximately 1550 feet, about 100 feet taller than the Sears Tower. This would allow for only about 11.2 feet per floor, but is similar to the floor-to-floor heights of the 1969 John Hancock Center. If floor-to-floor heights of other contemporary skyscrapers (built in the early '70s) are used, the building is 1716 feet tall using the World Trade Center's height, 1824 feet tall using the Sears Tower's, and 1888.5 feet tall using the Aon Center's. A computer model of the building created by Ryan Thoryk and Michael Jehn estimates the building to be 1677 feet tall, almost exactly the height of the spire of Taipei 101. This estimation comes from the fact that the half-inch scale model used in the movie was about 70 feet tall (according to the book Special Effects: Wire, Tape and Rubber Band Style by LB Abbott), and each floor was scaled to be 12 feet (there was no floor height variance).

Based on the measurements Thoryk and Jehn provide, which appear to match well with the scale and proportions seen in the movie, an approximation of the area of the building can also be arrived at: 2.4 million square feet. This is considerably less than the Sears Tower's 4.5 million, or the 4 million contained in each twin tower of the World Trade Center. There are several plausible reasons for this.

1. It may be fictional architect Doug Roberts' reaction to then fresh architectural criticism of the Sears Tower and World Trade Center as being too bulky, and placing inner office workers too far from windows. True to these measurements and its name, the Glass Tower's interiors are portrayed as very bright and not at all claustrophobic.

2. It may also reflect very limited space in San Francisco. If San Francisco's zoning laws for skyscrapers are similar to those of New York (which set the standard), then the complete land area of the Glass Tower site may be as little as 4 times the square footage of the tower's upper floors, which would make it possibly less than 2 acres. This is quite small compared to the World Trade Center's 16 acres in lower Manhattan.

3. This may reflect its use for apartments in the upper floors. Office buildings can allow for more space between elevators and windows, but buyers of highrise condos and apartments would not tolerate many windowless rooms near the building's core.

4. Pressure from the community to avoid in San Francisco what in 1974 Manhattan was seen as a glut of rental space created by the World Trade Center.