An empty room in a dream often reflects potential more than lack -- space that hasn't been filled yet, waiting for a decision about what belongs there. It can also point to loneliness, depending on how the room feels: still and hopeful, or hollow and unsettling. The emotional tone usually matters more than the emptiness itself.
The Superior Planets are most efficacious; the inferiour are weak, and easily do suffer by the Superiours, and receive good or ill from them. - William Lilly (1602.-1681.)