Following the death of the Emperor in 4 ABY, warring factions within the quickly collapsing Empire waged destruction upon Coruscant. The Senate Building, along with the nearby Imperial Palace, sustained heavy damaged but proved resilient never-the-less. As the New Republic settled into its role as leader of the galaxy, the Senate Building was repaired and the New Republic Senate convened with its halls. It was within this room that Jedi Master Luke Skywalker made his plea before the assembly to allow him to reform the Jedi Order and begin searching for new recruits. With a majority backing, Skywalker pledged that the new Order would serve as protectors of the Republic, much as the Jedi had for millennia before the Empire.
While the structure had proven sound when attacked from the outside in the past, the same could not be said about an internal assault. In 17 ABY during a full session of the Senate, several detonations rocked the tower, hurling rubble onto the Plaza outside and collapsing the central speaking podium. After removing the dead and wounded, it was eventually discovered that the Dark Jedi Kueller was responsible for the attack. After the issue of the bombing was cleared up, the Senate Hall was gutted and new architects swept into the building and reworked the interior, so much so that many considered it a new complex all together.
While the New Republic struggled to establish itself, the galaxy was invaded by an alien race called the Yuuzhan Vong. As attacks against Republic worlds increased, Yuuzhan Vong representative Nom Anor addressed the Senate and encouraged the assembly to denounce the Jedi and hand them over to the invaders. Then Chief of State Borsk Fey'lya rebuffed Anor's plea and had him escorted off Coruscant. However, Anor was successful in increasing the anti-Jedi sentiment among the senators and many Jedi were turned over to the Yuuzhan Vong across the galaxy. As the Senate continued to debate how best to deal with the new threat to the Republic, the Yuuzhan Vong attacked Coruscant in force, breaking through its orbital defenses and smashing through into the skylanes of the city world. As mass evacuations ensued following a crushing victory by the invaders, the Senate Building was left relatively intact if abandoned.