If you want to float your house skyward with balloons like Carl Fredricksen does in the hit Disney-Pixar Animation Studios movie "Up," it's going to take a whole lot of helium.

According to Pixar, Carl's house in the film attains liftoff with about 20,000 balloons. But for the sake of realism, director Pete Docter and his crew wanted to know how many balloons it would take in real life to make the scenario plausible, which came in at 20 million to 30 million.

"We work with scientists, so they approached everything from a very logical standpoint and researched how much loft a balloon has to figure out (our scenario)," Docter said in a recent @ The Movies interview. "There's tons of research that goes into every detail, including Carl's house. The guy who designed it, Don Shank, consulted with an architect to learn how a house attaches to a foundation in modern day versus a house built in the teens or earlier. The house is stylized in the film, of course, but it started with reality."

So, while the idea of floating a house is scientifically possible, the idea of the talking dog collars in the film still remains a dream. Or does it?

"It's funny, a couple people sent articles to me saying, 'Hey, look! Talking dog collars already exist,'" Docter said, laughing. "So apparently there are products out there that claim to do that."

"Up" stars Ed Asner as Carl -- a 78-year-old widower who buoys his house with balloons to float to South America to fulfill a lifelong dream.

"Up" opened up at No. 1 its debut weekend and has earned more than $137 million in North American theaters since its May 29 release.