The dressing rooms and corridors of “Birdman: The Unexpected Virtue of Ignorance” were built on soundstages in the New York City borough of Queens. But they look so authentic that most people assume they’re actually backstage at the St. James Theatre off Times Square.

That’s just what Kevin Thompson likes to hear. As the movie’s production designer, Thompson grappled with quite a few challenges, made all the hairier by director Alejandro González Iñárritu’s desire to make the whole film look like it was shot in one long take.

The movie, considered by many oddsmakers to be the best-picture favorite at Sunday’s Academy Awards, stars Michael Keaton as Riggan, a former blockbuster action hero trying to reframe his legacy by staging a serious play on Broadway. The action flits between real and surreal moments, with the camera rarely appearing to stop for a cut.

“It was interesting, because we had to get extremely technical to make everything work for the camera and lighting on these long takes,” said Thompson, a Minnesota native who trained as an architect. “Then we had to make the scenes look continuous by tying them together with elements of scenery.”

On top of that, he had to satisfy Iñárritu’s “need to feel the emotional aspects of the theater and these characters,” Thompson said. “He’s a very passionately creative director, a quality that doesn’t always go hand in hand with the technical side.”

Thompson was not nominated for an Oscar for “Birdman,” but recently won the Art Directors Guild’s top prize for excellence in contemporary production design, a peer-to-peer award he calls “the next best thing. Quite often contemporary settings don’t get considered by the academy because people don’t understand all the work that goes into it.”

Thompson estimates that 80 percent of the film was shot on the soundstage, where he painstakingly created that backstage world of cluttered dressing rooms and dank halls that look so real you can almost smell the musty air.

More important than choosing the right lived-in props and faded, moody colors was constructing a modular set that “could grow and shrink according to the amount of time actors had to get from Point A to Point B, depending on the amount of dialogue and how quickly they were walking.”

For that, he got an assist from graphic designer Eric Helmin, another Twin Cities native (Apple Valley) who has worked on movies by the Coen brothers and Wes Anderson. Helmin, who designed the movie’s “Birdman” posters and the marquee for Riggan’s play, also made giant illuminated boxes, computer-generated façades for fake granite “walls” and massive backdrops light enough to be whisked around in seconds. Pieces like these served as transition devices to visually stitch together different locations, making the actors’ journeys from one to the next look seamless.

“Because of the immediate turnarounds we had to do on the set, I kept a 300-pound printer with me that could print 4 feet wide,” said Helmin, who recently moved back home to do design work for the Minneapolis Institute of Arts. “The movable wall pieces and lightboxes would act as cinematic airlocks between the sound stages in Queens and the real locations in Manhattan.”

The two men perfected this technique on the movie “The Adjustment Bureau,” making Matt Damon appear to jump through magical doors to different settings.

Thompson wound up building a three-story maze of those movable walls and ceilings to accommodate both the practical necessities of the long takes, and to create effects meant to mirror Riggan’s increasing anxiety.

“We would make the ceiling lower and the halls narrower, more claustrophobic, when he’s breaking down,” he said. “The theater itself became one of the movie’s most important characters.”

If you thought of those creepy halls with the geometric-patterned carpet in Stanley Kubrick’s “The Shining” while watching “Birdman,” it’s no coincidence.

“Kubrick was one of our inspirations,” Thompson said.

The wildest scene came when Riggan, locked out of the theater and clad in just his underwear, must navigate a tourist-packed Times Square. The unpredictability of shooting there — even at 2 a.m. — was daunting enough. Then there was the pressure of doing it in one take.

“We had to get Michael out of the theater, onto Times Square moving through a crowd, and back to the front [of the theater],” Thompson said. “We had crew pretending to be tourists taking video on their phones, plus a marching band to act as a protective wall around him. But a lot of people didn’t recognize him. They thought he was just some crazy, wandering guy.”

‘Working Girl’ to working guy

Thompson, who grew up in the northwestern suburb of New Hope, got a degree in architecture from the University of Minnesota in 1978.

After moving to New York, where he renovated the brownstone belonging to Sigourney Weaver’s character in the movie “Working Girl,” he decided to try production design himself and wound up working on several notable indie films, including Harmony Korine’s “Kids” and the Parker Posey vehicle “Party Girl.”

He developed a reputation for a “New York, not Hollywood” style and an ability to accommodate directors with strong, singular visions that brought him higher-profile projects like the George Clooney film “Michael Clayton,” “The Bourne Legacy” and Judd Apatow’s upcoming “Train Wreck,” while still doing edgy indies like “Under the Skin.”

Next up: “Money Monster,” directed by Jodie Foster and starring Clooney as “a financial guru with a talk show who gets held hostage on the air,” Thompson said. “It plays out in real time.”

After “Birdman,” that should be a breeze.