Concept: the Movie Elevator™
It’s an elevator right against a wall that has every frame of a movie stacked, and the elevator drops at a rate of 24 fps.
that would be wildly unsafe as an elevator (or as an escalator as i first read your post). But a neat idea.
Exactly how tall would a building have to be for a 15 minute film? or are you thinking of keeping the film at actual size? (then you would need a projector to see anything.)
Full size of a theater screen in a very, very tall building.