Trivia: There are more than a few Hitchcock references in this movie. Most notably Harrison Ford's character - Norman (Psycho), suspecting the neighbour of murdering his wife (Rear Window), Michelle Pfeiffer falling in the shower and pulling the shower curtain down with her (Psycho). There are many others if you watch for them.
Trivia: There are quite a few close-up scenes filmed through glass, on the floor, with the camera on the bottom side and the actors on the top side. For example, when Claire is paralysed, Norman bends down and talks to her before picking her up and carrying her upstairs - when they are downstairs, Claire is lying on glass with the camera filming her from below.