Geoffrey Rush was never meant to look like Vincent Price (star of the original film House on Haunted Hill (1959)). The original screenplay described Stephen Price as a regular looking businessman. Rush didn't care for this, so he suggested that his character look like the film director John Waters. The director agreed to test this look out. After his transformation, he ended up looking so much like Vincent Price the director decided to keep the look.
(at around 18 mins) Famke Janssen performed her own stunt when the glass ceiling breaks. It was extremely important for Janssen to remain where she was and very still, yet even with her basically glued to the spot, the shard hit with so much impact that it bounced her head off the table as you can see on close inspection of the scene.
William Malone got the idea to set the movie in a former insane asylum when he was filming an episode of Tales from the Crypt (1989) in a former asylum and noticed that crew members were running scared out of the basement, not wanting to film there.
The rollercoaster in the beginning of the movie is The Incredible Hulk at Universal's Islands of Adventure in Orlando, Florida.
This film and Thir13en Ghosts (2001) were Dark Castle Entertainment's first films, and a remake of horror filmmaker William Castle's films House on Haunted Hill (1959) and 13 Ghosts (1960). The studio took its name from him.