Much as energy can get stuck in your personal energy fields, so can it get stuck in architectural and geologic space. Perhaps you've noticed that there are rooms that always somehow make you uncomfortable, or where you always seem to fall into argument. Maybe there's a house in your neighborhood where no one stays long and one after another sound marriages go sour. It's not healthy to live in a space where old strife lingers. A space clearing releases the old patterns so that you can start fresh.
This is a good thing to do before you move in to a new space, or in preparation to sell, or in response to tumultuous times.