Mike,
My layout is built above the ground by about 18". Here's a picture during setup. I don't have a real tree, but you could put one in the center if there were a few less buildings!
My platform is 5' x 9'. The white-felt covered plywood is 3/4" so it would hold a large tree if needed. There are 3 columns that hold it up in the front - the back rests on the window sills.
It works really well because we stash all of the Christmas presents under the layout. Lots of room for presents for the whole family!
And with presents...
It may give you some ideas...
Ed
