Things I changed were:
You need all of your 9th grade geometry when doing the calculations for the height and width of the walls. The cool thing able the yurt design is that you do not have to be that accurate. The yurt adjusts quite a bit. If the circle is a little bigger the walls are a little lower - there is a fair amount of play in the system.
Learn how to tie knots!
Spring 2009 I built a platform for the yurt. I used a very easy and simple design for a 16x16 square DekBrands Floating Foundation Deck System.