The story of how Don Hall and Chris Williams, codirectors of the Oscar-nominated animated hit “Big Hero 6,” first came to work at Disney almost sounds like something out of a Disney movie.

Growing up far removed from Hollywood – Hall in the small town of Glenwood, Iowa, and Williams in Waterloo, Canada – both fell in love with drawing at an early age and both were deeply affected by classic Disney animated movies such as “Peter Pan,” “Bambi” and “Dumbo.” When each was hired by Disney to work as a story artist, it felt like the fulfillment of a wildly improbable dream.

“It’s hard to even describe how it felt to get that phone call,” Williams, 46, recalled recently.

Hall, 45, nodded. “Saying you wanted to work at Disney,” he said, “was like saying you wanted to fly to the moon.”

In the two decades since, Hall and Williams have seen a lot within the walls of the Roy E. Disney Animation Building in Burbank, Calif. They’ve seen jubilant times when it seemed the studio could do no wrong, cranking out hit after hit. They’ve seen grim, demoralizing times when those hits dried up and it seemed the studio could do little right.

But on a warm winter afternoon, as Hall and Williams, along with a third key member of the “Big Hero 6” team, producer Roy Conli, looked around the building where they’d spent the bulk of their careers, they saw not much at all.

Normally bustling with hundreds of people working on the studio’s animated features, the 20-year-old building is now largely empty, the artists, writers, directors and other personnel relocated nearby while the building undergoes a 11/2-year renovation. Furniture has been moved. Carpeting has been pulled up. Save for a few stray drawings left behind, the walls have been stripped bare.

“This is the first time I’ve been back since they started tearing things down,” Williams said, sitting with Hall and Conli in a once-busy, now-empty communal area formerly known as the Caffeine Patch, where staffers would gather to socialize and fuel up on coffee and snacks. “To see this kind of carcass of what it used to be is very strange. We all galvanized around this place, and now we’re being split up. It’s an emotional time.”

There may be a twinge of sadness at seeing this place where so many movies have been made now barren. But to Hall, Williams and Conli, the renovation is actually a testament to the studio’s renewal.

Ten years ago, Disney Animation was in a deep slump, not unlike today’s DreamWorks Animation, which last month slashed 500 jobs in the wake of a string of box office disappointments. Morale was low, and some thought that what once had been the heart of the Disney creative empire could end up being shuttered.

Then, in 2006, the Walt Disney Co. acquired Pixar Animation Studios in a $7.4-billion deal and brought on Pixar heads John Lasseter and Ed Catmull as, respectively, chief creative officer and president to oversee the studio’s animation division. Lasseter and Catmull quickly set about changing the studio’s culture, shifting from an executive-driven model to a filmmaker-driven one.

In the ensuing years, Disney has turned out a string of animated blockbusters, including “Tangled,” “Wreck-It-Ralph,” “Frozen” and now “Big Hero 6,” which has grossed roughly $500 million worldwide.

“We felt that if we could give this group of talented artists a big hit, it would heal this studio – and it did,” Lasseter said. “They are so empowered. They believe in themselves now. This studio is on fire.”

Along with rejuvenating Disney Animation, Lasseter and Catmull were bent from the outset on overhauling it physically too. They used Pixar’s headquarters in Emeryville, Calif., which opens up into a vast, open shared space, as a model.

“If you go to the Pixar building, the first thing you see is this gigantic atrium,” Hall said. “No matter what, even if you’re just getting coffee, you’re going to run into somebody else, and that’s going to spark conversations.”

Then-Pixar Chairman Steve Jobs, who was centrally involved in designing the studio’s main building (which now bears his name), along with the architectural firm Bohlin Cywinski Jackson, strongly felt that those spontaneous conversations were critical to fueling creativity.

“Steve believed in the unplanned meeting, where you run into somebody in the halls, and Pixar was designed with that in mind,” Lasseter said. “(Disney’s) animation building was 100 percent the opposite of that. It was really not conducive to creativity at all.”

Designed by Robert A.M. Stern Architects, the 240,000-square-foot building had originally been divided into offices that left staffers often feeling isolated from one another. One of Lasseter and Catmull’s first steps after taking over was to remove some interior offices to create the Caffeine Patch. To boost the sense of corporate openness and transparency, they put their own offices in the center of the building where everyone could easily see and access them.

“All of a sudden, communication amped up a good 50 or 60 percent,” said Conli, 55. “It was a wonder.”

Extending that principle, the renovation (the estimated cost of which Disney would not disclose) will create a large, open communal space where employees can gather, eat and share ideas. “The whole center of the second floor will have an atrium that will go up two stories,” Lasseter said. “We want to make this building so beautiful that it’s worthy of the artistic talent that’s there.”

Under the plans developed by the firm Lever Architecture, the building’s exterior will remain largely untouched, except for one major change: The blue “Fantasia” Sorcerer’s Cap, which once housed the office of Roy Disney, nephew of Walt Disney and longtime senior executive at the company, will become the building’s main entrance.

“There will be a gorgeous stairway that goes up into the hat,” Lasseter said. “It’s a really great symbol, like you’re entering the building through the magic of Mickey Mouse’s hat.”

When Hall and Williams came to work at Disney in the mid-1990s, that magic seemed to be flowing at full strength, as the animation division was in the middle of what came to be known as the Disney Renaissance. “You felt like you were a rookie on the Lakers during a dynasty,” Hall remembered.

But by 2000, the dynastic power had shifted north to Pixar, and the traditional hand-drawn animation that had been at Disney’s core for decades was quickly being overtaken by computer-generated animation. Disney’s animation division began to lose its way with duds like “Atlantis: The Lost Empire” and “Treasure Planet,” and hundreds of animators were laid off. Disney currently has about 800 animation staffers.

“We weren’t telling stories that reflected what we wanted to tell, and that led to some of the darker times here,” Hall said. “When John and Ed came, it felt like, ‘This is what we’ve waited a long time for.'”

While Lasseter and Catmull brought their highly collaborative approach from Pixar over to Disney – and are now, in a sense, Pixar-izing the Roy E. Disney Animation Building – they have otherwise drawn a hard line between the studios, insisting that each maintain its own separate teams and identities.

Even as the building renovation proceeds, Disney’s animation division is pushing ahead on its next two releases: a fox-on-the-run story called “Zootopia” and a seafaring adventure called “Moana,” both due in 2016.