I am not at home right now, so I can't find out for sure about this.
But I have a screened-in back porch which is about 10x10 (stall size!

). And the design is rather cute . . . it starts off with a typical treated wood lumber deck, from which there rise the corner posts and some "stud" posts about 36" apart.
What then makes up the walls is simply a whole bunch of wooden screen doors like the type I can get at the local hardware store for around $20-30 depending on whether they are on sale or not. Each side of the enclosure takes 3 screen doors 36" wide, making about 9 feet or 10 feet (like I said, I'm not home, so I can't check.)
The reason I bring up this design is that I let my little fiends out on the back porch regualarly, and in fact installed a pet door so they can come and go freely. But the mesh on those screen doors was horrible at keeping them in. One of them in particular I call my "can opener." He gets one tooth in and just keeps working it more and more.
I kept taking those screen doors off and trying different meshes, and every season it was yet another battle with the kitties over those stinkin' screens! What I ended up resorting to was a wire mesh metal that I think is about 1/4" squares. I also think it may have said it was "galvanized"?? That worked great over those screen door screens.
So if you wanted to try something similar, you just need to go see what those screen doors will run ya, build a frame of whatever size you want, and reinforce the screens with some of that metal mesh.