"As you approach, the Great Hall and the tower housing Professor Dumbledore's office are off to the left, and there's a viaduct connecting them to a series of buildings on the right. If you look to the right of that viaduct, there are considerable changes there": a whole new set of towers and spires. "Sometimes it was done to improve a particular shot, but sometimes it was just because I was anxious to improve the silhouette. Nobody's objected so far, and hopefully they won't."

Hagrid's house was an octagonal one-room hut in the first film, but Craig added a bedroom in the back. "We're quite cavalier about our ability to change things," he says. "The restriction is always money. If the studio already paid for something, they don't particularly want you to go and change it." (The films have grossed $3.5 billion worldwide, so Warner Bros. can afford a hut extension.)

The main entrance to Hogwarts is new. The first movie used a real location, Christ Church College at Oxford. For the second film, it was replaced with a built set.

Hogsmeade Station has been reconceived for "Phoenix." It had been an actual location in the North Yorkshire moors. For this film, Craig created a new set in the woods near Pinewood Studios.

The trees in the Forbidden Forest are bigger. And speaking of growth, the beds in the Gryffindor dormitory have been extended — ditto the classroom desks — to keep pace with actors who've become teens.

Craig is now designing sets for the sixth film, "Harry Potter and the Half-Blood Prince," including the astronomy tower where a beloved character will plummet to his death. "It has to be impressive and beautiful and poignant," Craig says. "So I'm looking forward to doing that."

He's also anxious to get his hands on J. K. Rowling's seventh, and final, book in the series, "Harry Potter and the Deathly Hallows," due in stores July 21, one week after "Phoenix" hits screens. "I can't wait," he says. "We need to know which sets to retain for the last film." Not that he'll get an early peek. "I never have before," he says, and laughs. "I just have to go to the bookshop" — like every other fan.