Like a hill, in the rear, the bed should be against a wall. There should be no windows or doors behind. If your bed is placed immediately under a window, then support is sorely lacking.
The rush of energy from the window also causes restless sleep. Space on the sides of the bed is important. Otherwise the sleeper feels cramped in life.
Bed under the slope or beam is bad. Sleeping under slope causes ill health, bad luck and relationship problems. A beam above causes back-stabbing abs jealousy. One remedy is to install false ceilings.
Do not place the bed against the toilet wall. The harmful yin energy from the toilet will bring about ill health and loss of opportunities.
Do not place your bed opposite mirror. Mirrors in the bedroom which reflect the sleeping couple, suggest the intrusion of third parties encouraging infidelity.
Do not place your bed facing open shelves. Shelves constitute poison arrows, and cause misfortune, ill health and quarrels. Close the shelves with covering doors.