A four-story glass structure was erected on the site of the South Court, an enclosed courtyard on the Main Branch's south side, starting in the late 1990s.
The structure cost $22.2 million and included a floor area of 42,220 square feet (3,922 m²).
Opened in 2002, the South Court structure was the first permanent above-ground addition to the Main Branch since its opening.
The pop-up reading room in Bryant Park was re-established in summer 2003.
The "room" contained 700 books and 300 periodicals.

By 2004, streaks were already blackening the white marble and pollution and moisture were corroding the ornamental statuary.
According to The New York Times, "tiny particles of rubber scattered by passing car tires have accumulated on the building, mixing gradually with water to turn the marble into gypsum, which causes the outer layer to crumble in a sugaring effect."
In December 2005, the Lionel Pincus and Princess Firyal Map Division space, with richly carved wood, marble, and metalwork, was restored.

In 2007, the library announced that it would undertake a three-year, $50 million renovation of the building exterior, which had suffered damage from weathering and automobile exhaust.
The marble structure and its sculptural elements were to be cleaned; three thousand cracks were to be repaired; and various components would be restored.
All of the work was scheduled to be completed by the centennial in 2011.
Library director Paul LeClerc said in 2007 that "my ambition is for this to be the building you simply must see in New York at nighttime because it is so beautiful and it is so important."
By late 2007, library officials had not yet decided whether to try to restore damaged sculptural elements or just clean and "stabilize" them.
Cleaning would be done either with lasers or by applying poultices and peeling them off.

Stephen A. Schwarzman donated $100 million toward the renovation and expansion of the building, and in April 2008, the library announced that the main branch building would be renamed in his honor.
As a condition of the gift, Schwarzman's name would be displayed at each public entrance.
Later that year, British architect Norman Foster was chosen to design the Main Branch's renovation.
To pay for the renovations, the New York Public Library was attempting to sell the Mid-Manhattan and Donnell branches, the latter of which had already found a buyer.
Nicolai Ouroussoff, former architecture critic for The New York Times, opined that Foster's selection was "one of a string of shrewd decisions by the library that should put our minds at ease".
A four-story glass structure was erected on the site of the South Court, an enclosed courtyard on the Main Branch's south side, starting in the late 1990s. The structure cost $22.2 million and included a floor area of 42,220 square feet (3,922 m²). Opened in 2002, the South Court structure was the first permanent above-ground addition to the Main Branch since its opening. The pop-up reading room in Bryant Park was re-established in summer 2003. The "room" contained 700 books and 300 periodicals.
By 2004, streaks were already blackening the white marble and pollution and moisture were corroding the ornamental statuary. According to The New York Times, "tiny particles of rubber scattered by passing car tires have accumulated on the building, mixing gradually with water to turn the marble into gypsum, which causes the outer layer to crumble in a sugaring effect." In December 2005, the Lionel Pincus and Princess Firyal Map Division space, with richly carved wood, marble, and metalwork, was restored.
In 2007, the library announced that it would undertake a three-year, $50 million renovation of the building exterior, which had suffered damage from weathering and automobile exhaust. The marble structure and its sculptural elements were to be cleaned; three thousand cracks were to be repaired; and various components would be restored. All of the work was scheduled to be completed by the centennial in 2011. Library director Paul LeClerc said in 2007 that "my ambition is for this to be the building you simply must see in New York at nighttime because it is so beautiful and it is so important." By late 2007, library officials had not yet decided whether to try to restore damaged sculptural elements or just clean and "stabilize" them. Cleaning would be done either with lasers or by applying poultices and peeling them off.
Stephen A. Schwarzman donated $100 million toward the renovation and expansion of the building, and in April 2008, the library announced that the main branch building would be renamed in his honor. As a condition of the gift, Schwarzman's name would be displayed at each public entrance. Later that year, British architect Norman Foster was chosen to design the Main Branch's renovation. To pay for the renovations, the New York Public Library was attempting to sell the Mid-Manhattan and Donnell branches, the latter of which had already found a buyer. Nicolai Ouroussoff, former architecture critic for The New York Times, opined that Foster's selection was "one of a string of shrewd decisions by the library that should put our minds at ease".
New York Public Library Main Branch