The New Avengers Facility previously served as a warehouse of Stark Industries owned by Howard Stark. With running of the time and Stark's death this place was abandoned until the Avengers took up residence here.
After defeating Ultron the Avengers decided to move to a new base which was formerly a Wherehouse of Stark. In 2015, Nick Fury went to the New Avengers Facility to inform Black Widow about the possible location of Bruce Banner. Meanwhile, Thor and Tony Stark said goodbye to Captain America as one returned to Asgard and the other wanted a normal life. Later, Captain America and Black Widow led the first training of the New Avengers which consisted in: Falcon, War Machine, Scarlet Witch and Vision.
A couple of months later, Falcon was in charge of protecting the New Avengers Facility. During his watch, he realized that someone had infiltrated into the facility with unknown reasons.
That someone was Scott Lang, who presented him as Ant-Man. Wilson asked Lang the reason of his infiltration; Lang replied that he only was looking for a device that he needed. That answer did not like Falcon and immediately attacked Lang, who using the skills of his suit and attack techniques that Hope showed managed to defeat an Avenger. After his defeat, Falcon asked to someone not to tell Cap about what happened.
A year after the defeat of Ultron, Thadduess Ross visited the New Avengers Facility with Tony Stark and he presented the Sokovia Accords to The Avengers; Captain America, Black Widow, Falcon, Scarlet Witch, War Machine and Vision and than left to allow them to discuss the Accords amongst themselves and telling them, if they refuse to sign it will be seen as an act of resignation.
As The Avengers debate the Accords, Tony Stark supports the Accords with James Rhodes, Natasha Romanoff and Vision. Steve Rogers however doesn't agree with him, along with Sam Wilson and Wanda Maximoff. Later, Tony Stark confided Scarlet Witch in the facility until the Accords cool off with Vision giving her company, and also Hawkeye infiltrated the New Avengers Facility to save Scarlet Witch.
Tony Stark later arrives to the facility after The Avengers have been divided after the Avengers Civil War where Captain America, Falcon, Black Widow, Scarlet Witch, Hawkeye and Ant-Man are runaways, where he helps Rhodey after the misfire where he was parlayed. Tony than received a package, delivered by a FedEx driver from Rogers with a letter and phone apologizing to Stark for not telling him about his parents and promised to be their if he ever needed them.