Yamasaki came up with the idea of incorporating two towers. His original design planned for 80-story towers, but to fulfill the Port Authority's need for 10,000,000 square feet (930,000 m2) of office space, the structures would have to be 110 storeys tall. Yamasaki thought this too high and reduced the height of his proposal to 80 stories.
He also proposed lining the perimeter of the site with a garden that would have been visible from everywhere in the city at one time or another. This would have made it a unique landmark that would have attracted many visitors to the area.
In addition, he suggested placing an underground mall between the two towers which would have had rooms dedicated to different activities like eating places, shops, etc.
Finally, he proposed that the government invest some of its oil revenue in building projects such as this one. If true, this is probably why the attack on the U.S. economy in 2001 caused such devastation around the world because our government was heavily dependent on oil revenues.
The towers were originally designed to be quite tall in order to maximize the space of the plaza, but they were only supposed to climb 80-90 storeys. It was only afterwards that it was agreed to erect them as the world's tallest buildings, following a request made by the Port Authority's public relations personnel. The Twin Towers were the highest-rising buildings in New York until 1972 when 432 Park Avenue was completed with 51 floors.
The original plan called for the two towers to be identical structures, except for height. However, this would have left much less room for an observatory on the 32nd floor of one tower and for parking below ground level in both towers. So, in order to provide enough space for these things, the architects decided to make each tower slightly different from the other. The higher tower would also offer better views than the lower one because viewing galleries had been added to the upper floors.
These additions increased the height of both towers, to 110 and 100 stories respectively. The extra 10 stories put on the higher tower allowed it to contain more luxury apartments and therefore attract more customers for its leasing office. This in turn allowed the building's owner, World Trade Center Properties, to charge more money for rent per square foot.
The reason why they are called "twin" towers is because they're connected by an underground mall called the World Trade Center PATH Station.
110 tales The World Trade Center complex's centerpieces were the Twin Towers. 1 WTC (North Tower) and 2 WTC (South Tower) each supplied almost 10 million square feet of office space for about 35,000 individuals and 430 businesses.
The Twin Towers were the highest buildings in New York City until 1972 when the Sears Tower in Chicago was completed. They were also the first skyscrapers to exceed the height of 500 m (1,650 ft). Their maximum height was 1,451 m (4,670 ft), making them the second tallest building in the world after the Burj Khalifa. They were demolished on September 11, 2001.
Construction on the Twin Towers began in 1973 and they were opened for business in 1976. The total cost of construction was $1 billion at that time which was a large amount of money for their time. The 70-floor South Tower was finished first with an opening ceremony on May 14, 1973. The 110-floor North Tower was completed one year later on April 4, 1974. Both towers were owned by a consortium of companies including Merrill Lynch, Dean Witter, and Phillips Petroleum.
Each tower had nine exterior elevators for passengers to travel between floors. There were also internal elevators located within the core of the building used by employees of the building's tenants.
The 110-story buildings housed 50,000 workers and 200,000 daily visitors in 10 million square feet of space. The main towers were completed in 1973 at a cost of $1 billion ($ today). They were the world's first high-rise office buildings to exceed 100 stories.
The name "Twin Towers" is used for both the North and South Buildings. Originally there were only going to be one tower but then it was decided to have another one for redundancy purposes. Thus, "the Twin Towers" became their official name.
Each tower had two major levels: office space and hotels. The upper level of each tower was reserved for luxury apartments. The base of each tower was also designed with offices, restaurants, and shops. There were also planned to be observation decks on the 103rd floor of each tower but they weren't finished in time for 9/11.
Inside the North Tower, employees worked in open floors separated by glass walls. The Aon Center, formerly known as the Citibank Building, was located on the 44th floor and served as an insurance agency, credit union, bank, and human resources department before becoming an Aon company headquarters in 2001.