You may have 8sq ft but once you cut hole in floor that's going to eat up at least 2 sq ft of floor space. I wouldn't squeeze more than 2 at most. Really just 1 in my opinion. Looks good so far though.
I was going to get one PTH when I picked up 4 other hens, but the guy said he couldn't guarantee me a PTH hen, they are about 12 weeks old. So I didn't take the chance