I misunderstood, I thought you got the idea at the show yesterday when talking to some folks from the forum. 
Your comment though does bring up the question of how you envision your 2nd level being supported. It may be too early to mention this, but with the yard beneath the loop, the design assumes that section of the 3/4" plywood decking will be supported by pylons while the rest can be on a grid, something like shown in the photo. The black lines are the grid frame, the gray is the decking over the yard supported by pylons, the black circles.
