When placing a bed on a wall with windows, it is best to place it with the head against a solid wall to the right of the windows. In the interest of balance and symmetry, the bed should be centered on the wall without taking the windows into account. This arrangement takes into consideration feng shui positive energy flows and is traditionally sound bed placement as well.
Where a wall with windows forms a right angle with a solid wall, the head of the bed is placed centered on the solid wall. If necessary to maximize floor space in a small room, instead of centering the bed on the solid wall, position it against the wall with windows in the apex of the right angle. The result would keep the head of the bed against the solid wall with the edge of the bed in line with but not in front of the window or windows.
According to feng shui, placing a bed under a window (head toward window) is the most unsatisfactory placement. From a purely pedestrian consideration, having a bed under a window can result in uncomfortable draftiness. To mitigate “bad energy” and drafts, when the size and orientation of a bedroom dictate placing a bed under a window, having a large solid bed headboard and sturdy draperies installed as window coverings minimize drafts. Placing a bed without a headboard under a window lets the curtains then take the place of a headboard in the sense of functioning as a focal point.
For those more concerned about the view of a nice sunrise when waking in the mornings than the natural energy flow tenants of feng shui, the head of a bed could be placed centered on a solid wall opposite and in line with a window to maximize the favored view.