Thanks for the welcome.
Part of my horse barn has about a 10'x12' 3 sided covered shelter area, probably built for storing hay. So far, I've extended a 20'x10' run off of that for the birds, and currently have a small 4'x4' covered brooder pin that the birds call home. The birds are at 20 weeks, and it's time for the real deal. Since I already have 3 sides, and a roof, I thought building a 4th wall w/ door and windows would be a good use of that part of the barn, and obviously reduce expense of the coup. It would be a ground level coup though. Flooding and rodents are not a problem.
I think I may stick w/ a ground based design unless someone comes up w/ other info talking me out of that.
Thanks!