Don't know if this is applicable to anyone else, but my 'house' dreams often show hidden rooms/suites, and basements below basements.
Perhaps they are indicative of 'secrets', experiences, or imaginations from long-gone ancestors. Not as 'ghosts', but as cellular memories and habits I inherited.
If this is a possibility, I'd best look for ways to calm these echoes. So far, they aren't frightening...just a bit confusing...even interesting.
Most interesting of all is that I recognize houses from previous dreams, though they change. None return me to the exact same house, only similar.