Build this predator-proof, portable chicken coop for your backyard. This new and improved incarnation of the portable chicken coop is designed for three to four chickens, and anybody can build it. From MOTHER EARTH NEWS magazine.
I like this one but with the interior area higher off the ground for easier cleaning - see side pic of nest boxes in next image. Coop dimensions: 4x4ft for 4-5 chickens, total run area, 4x12 ft (includes under the coop). Use 1x1" welded wire (rabbit wire) to keep predators out (not chicken wire). And larger wire on base to prevent entry by digging (10cmx15cm rectangular wire). Use 'dog door' flaps at roost entrance to trap heat. Add carribeaner to next box flap to prevent egg stealers.