My son and I built a chicken tractor partially out of recycled materials. Here is the finished product.
The run is 8 feet by 4 feet. The indoor roosting area is about 42"x42" with two external nest boxes (buckets). It cost between 200-300 dollars to make and I spent a couple weekends (only a few hours per weekend) building it. Note that the wheels rotate under lifting the coop. When they are rotated out, the coop sits flat.
We started with a used built in cabinet that was for sale at the Habitat Store. This is a place that sells used building materials.
Here you can see that we knocked out the shelf. The top was not attached which was helpful as the whole thing was turned face down and the top became the access door to the coop as seen below. I used one of the doors from the cabinet to make a door into the coop on the front of the run.
The floor of the roosting area was covered with hardware cloth and a door was cut. THe whole coop was covered with corrugated metal roofing in 10 foot strips.
We built the run with 2"x3" welded wire fencing that was covered with green plastic. I began by attaching the fencing with poultry staples, but this was tedious. I saw on another coop design that someone drilled pennies to make washers which were screwed on to hold the fencing. This was much faster and looked nicer.
I cut holes in the sides of the box to allow the birds to enter the nests. The nests are standard bucket with sealing tops. I cut the tops to fit the holes on the sides and screwed them to the cabinet. The nest boxes will now pop on and off, but it is tough to do.
a few more views.
Lessons learned: Do not use the cull lumber from Home Depot. Choose very straight 2x4's otherwise your corners will be awful. A few of mine were. Build the whole thing and put the fencing and roof on last. Add 50% to your budget because of screw ups and problem solving. Add 100% to your estimated build time.
Keep some beer in the fridge and consider major setbacks "refreshment opportunities". My first grader helped too. When I said "Oh NO!" he would say, do you want me to get a beer, Dad"
If you have a large rear end (the result of setbacks and refreshments) getting in the coop through the cabinet door will involve some contortions and foul language.