The northwest corner of the building's base contains the eight-story cylindrical facade of Nasdaq MarketSite, which includes a large LED sign.

The building contains 1,600,000 sq ft (150,000 m2) of floor space, much of which was originally taken by publishing company Condé Nast and law firm Skadden Arps.

[2] 4 Times Square, as well as the Bank of America Tower and Stephen Sondheim Theatre to the east, comprise the entire city block.

[15] The original antenna mast measured 132 ft (40 m) and was built primarily for Clear Channel Communications (now iHeartMedia, Inc.) as a backup transmitter site.

[34] In addition, the mast has been used as a backup site for FM stations such as WKTU, WNYC, WPAT, WSKQ, WHTZ, WAXQ, WWPR, WLTW, and WCAA.

[40] In a 1996 press release, Fox & Fowle described the character of the masonry facade as presenting "a more composed personality appropriate to the context of Midtown Manhattan".

In 2000, after the building opened, panels with the name of wireless provider Teligent Telecom were installed on the top stories, measuring 70 by 70 ft (21 by 21 m).

[67] As part of an agreement with Consolidated Edison (Con Ed), which operates much of New York City's power-supply system, the cells must be turned off during a power failure, such as the Northeast blackout of 2003.

[21][64] The fuel cells would have to run continuously to operate efficiently, since they could not be turned off or on easily, but the building's power needs were much lower at night during the day.

[78] When the building opened, the retail space was occupied by a three-story ESPN Zone entertainment restaurant, operated by The Walt Disney Company.

[91][94] The New York Daily News said that James Truman, Condé Nast's editorial director, "spent months thinking about nothing else" during the design of the cafeteria.

[99] The floors were resurfaced in white oak; the leather seats and tables were replaced; and the titanium walls were covered with curving sheetrock and plaster.

[101][102] The company's flagship magazines Vogue and Vanity Fair had their own stories, while The New Yorker had floors 20 and 21; the rest of the space had corporate offices.

[101] Most of Condé Nast's stories were shared by two publications; the elevator lobbies served as a common reception area, with glass doors on either side.

For example, Anna Wintour of Vogue used aluminum chairs and potted bulbs to resemble a setting in Home and Garden magazine, and Ruth Reichl of Gourmet designed her offices in a contemporary style with red accents.

[109][110][111] Furthermore, as part of the West Midtown special zoning district created in 1982, the New York City government had allowed new buildings in Times Square to be developed with an increased floor area ratio.

To ensure the area would not be darkened at nightfall, the city passed zoning regulations that encouraged developers to add large, bright signs on their buildings.

[113][114] Durst himself had acquired a small portion of what would be Park Tower and Prudential's office building, part of 20 lots on the same city block that he owned by February 1990.

[38] That October, law firm Skadden, Arps, Slate, Meagher & Flom agreed to move its headquarters to 4 Times Square,[125][132] with 660,000 sq ft (61,000 m2) on the top 21 stories.

[145] A construction crane fell onto a building on 43rd Street in January 1998,[146][147][148] and a piece of aluminum dropped from the northern facade that April, though no one was hurt in either incident.

[150] The most severe incident occurred on July 21, 1998, when a construction elevator fell onto the nearby Woodstock Hotel, killing an 85-year-old woman and injuring twelve other people.

[169] In addition, Nasdaq and Condé Nast had disagreed over the proposed LED sign since the beginning of 1999, leading the two companies to seek an arbitration proceeding.

In response, Nasdaq said the sign was within the terms of its own lease and that, in any case, Condé Nast's graphic-arts department did not need natural light.

[173] Several radio stations had also been forced to move to 4 Times Square after the attacks, prompting the addition of an FM antenna for WNYC in March 2002.

[178] Meanwhile, in November 2002, Durst announced that he would construct a 358 ft (109 m) antenna mast atop 4 Times Square as a backup facility for radio stations that had broadcast from the World Trade Center.

[195][196] Nasdaq planned to expand MarketSite over the following three years;[197] the expansion included a 10th-story event space with a 2,100 sq ft (200 m2) terrace that would be able to accommodate 400 people.

[36][35] Muschamp said it looked like a custom design for Condé Nast, "whose stock in trade is the knowing mix of high style and popular culture".

[36] Karrie Jacobs of New York magazine also considered Fox & Fowle's design to be better than Johnson and Burgee's plan, adding that "It's the perfect building for a culture that consists of nothing but fragmented references to what has come before".

[30] The building was pictured in the August 1998 issue of Vogue magazine, which was published as scheduled despite the fatal construction collapse the previous month.

[30] Muschamp said the cylindrical facade would "make a dandy giant soda can, film spool, aerosol spray, or a current issue of House and Garden".