It does NOT have a metal frame, at least not like you think. It is slimsy. That is almost the same one I have, mine do not have the roof windows. Mine does not have a "metal frame" but there are some metal bars that go here and there, but nothing I would call a frame

so don't let that fool you.
Roof Windows have been known to leak !! i would Caulk around them like Crazy !Also when done, Caulk all around the base, inside and out. I only did inside and should have done both but it is water proof so far.
I have, for now, window screen over the door windows and put the plastic windows on for the Winter. Will change to wire this year. I also need to make another window somewhere, I just ran out of time least year.
Great price !! We don't have a Menards here
p.s., start another threaad when you actually start the build. that way you will start fresh and see all the pics you have from beginning to end.