Our coop was built from mostly reclaimed, recycled and reused materials. We had to purchase a few hinges and latches, but otherwise we found the stuff in our garage or otherwise acquired it. It says something for keeping those odds and ends that "you might need someday."
I started by reading several posts over the course of a couple of years. On the brink of paralysis by analysis, I took the plunge. I went to a local business and asked if I could have any of their old pallets. They gladly gave me a 12 foot long by 54" wide pallet made of oak. The cross pieces were 1" oak slats, 54" long and 5 1/2" wide. The long supports were 3 x 4 oak. There was plenty of trial and error.
The front of the hen house is about 6 or 7 inches higher than the back, allowing for rain to run off the back and out of the run. All but a board or two on each end is on a door that swings open, hinged at the top, to provide ventilation. The front has the window, so we can see our hens roosting or moving about in the hen house. It also provides natural light. The window swings open, similar in design to the back door. Both openings are covered with hardware cloth to keep our hens in and the predators out. Facing the front, on the left side, the end opens completely to allow access to clean the hen house. The ramp to the pop door is attached with hook and eye type fasteners for easy removal when the big door needs to be opened. The door has a smaller pop door that is left open for the hens. The other end has a three bay nesting box. Four hens often use one box.
Materials - I had to purchase the hardware cloth, screws, the hook and eye latches, and some of the hinges - about $68 at Menards. As previously stated, the siding is reclaim lumber from pallets. Some of the 2x4s were ones that I had stored from previous projects and some were reclaim from pallets. The plywood for the floor and next box was in the attic of the garage. The roofing metal was some that a buddy had acquired and gave us. The latches on the end door and pop door were from an old deck project. I found by accident that the latch that holds the pop door closed also works to keep it open. The roost is from a branch that fell in our yard, giving the hens a natural style perch. I cut holes in 2 pieces of 1" thick wood that hang from the ends, so it can easily be removed.
As far as the run is concerned, $50 in T-posts at Tractor Supply and some old woven wire fence that the metal supplier also gave us had us in business. The buddy that supplied the metal roof and fence also gave us 4 hens to start our flock. For the last 10 days or so, the hens have been giving us 3-4 eggs a day.
I'm sure we'll have many design changes that will be discovered in the next year or so. I figure I may sell this hen house and build another one down the road to implement those changes.