I'm sure I CAN put a pitchfork through it (but I could do that with metal if I were determined to try). I'm looking for something that I wouldn't put a pitchfork through routinely by accident.
Instead of windows, just drop it a foot or so (under a good roof overhang), and use wire up there. Heat and ammonia both rise so ventilation is needed most at the top.
Or do both. But make windows top-hinged so that they act as their own awnings.
This is my Outdoor Brooder with the tarp sides dropped so that I've got upper-level airflow -- the same thing on a smaller scale.
And here's a good link for a top-hinged window support:
https://www.backyardchickens.com/articles/window-support-for-top-hinged-windows.74810/