I just realized what the thread was that you were talking about. The one issue with the design that we have is you can't get much bigger then a 25' dome. Too many weak spots in the PVC if you try and build bigger than that. Anyway, I'll repost what I posted in my "needing to get our kitchen coordinator a ticket" thread
But yes, the doorways are huge. Basically about 15' wide by 8' tall.
There's a website with information about the structure design and the guy who first created it I'll post below. Easier than trying to explain it myself http://www.toad.com/gnu/clifs-shade-structure.html
My first year was in '05 with Swingers Lounge and the structure design had been in use for a few years by them before I joined. They got their design from Cliff (an Oregon Country Fair connection). Cliff told me they used to use bamboo for the design at one point. Anyway, me and some buddies took over Swingers Lounge in '07 and renamed the camp CarboFuckiNation, I renamed it again in '09 as RevoFuckinLution.
We did some updates and fixes to the design. The biggest one that won't be listed on the web page is that we switched the cross sections into a single metal piece. It's one cross of metal, about 1' square, that the PVC slides into. The pressure from bending the PVC keeps it in place. The other update we did was to take out the bolts that would keep the PVC connected and insert one and half inch PVC into the two inch PVC. The smaller diameter sticks out a foot and is screwed together on one end. This way we just slide the long poles over the smaller pieces and, once again, the pressure keeps it connected. Much easier than laying it all out, lining up the holes, putting in bolts, and twisting nuts on.
If you got any questions after checking out the web page, I'll be glad to answer them
I'm only an asshole on the Playa. Especially when you give me a megaphone.