The optical depth effect created by the compressed upper steps, is used as early-on as episode #2, "Be It Ever So Mortgaged", when we first see that the far edge of the back "lawn" is actually beveled up sharply to give the illusion of a more distant fence and a much bigger yard. Often very noticeable, especially in the last seasons, because of revealing camera angles and lighting. At least a big yard made sense for 1164 -- the mystery staircase never did.