my coop was made entirely from scavanged materials. Including the nails.
I got the wood from shipping crates. The nails were also scavanged from the crates as I took them apart. The chicken wire was donated by a friend who took down an old fence. The sides of the run were sides from a crate. The roof was recycled corrugated tine roofing. I had some screws in an old box somewhere and found some more in a dump pile. I scrounged a couple cabinet hinges for the side door and a cabinet handle for the door.
The back door is held on by a couple hooks that were found in a dig bin at a pawn shop for 10 cents each.
The only thing NOT recycled is the chooks in the coop. I bought them at Atwoods where I got the crates.