The Mushroom

The advantages of a Mushroom style layout are pretty obvious.  First and foremost is the height of the layout in relationship to viewing angles.  As can be seen in the drawing below, the lower level is set at 48" above the floor and the upper level is set at 53" above the elevated floor (21").  The second advantage is that one scene doesn't protrude or interfere with the other since the upper and lower levels are viewed from opposite sides.  On the other hand, there are disadvantages.  First, you need a reasonable ceiling height.  In my case, the ceiling height is 100" which I believe is close to the minimum for someone of my height, 6'3".  In addition, construction is certainly more complex than a conventional layout and for obvious reasons it won't work on perimeter walls.