[Leisurely]

Does any one think it would be feasible to convert a green house into a hen house by replacing the glass with plywood sheet or similar material.

[Aunt Sally]

I don't see why not  

It would give plenty of space.  No drafts, make sure it is well ventillated and easy to clean out  

[dawninspain]

You'd need to felt the roof to make it waterproof (a damp henhouse would not be good) but if it works what a good idea for a redundant greenhouse.

Do let us see some photos if you go ahead.

Dawn