Measure the camper shell, and make note of the dimensions. This is important regardless of the kind of coop you decide to create.
Clear brush and any other obstructions from the place where you intend to build the coop. Lay down two 2-by-4s that are as long as the width of the camper. Cut at least four 2-by4 pieces the same length as the length of the camper, and lay them across the first two pieces, parallel to each other. Place 3/4-ply CDX plywood on top of this.
Next, place the camper shell over the plywood. Open the windows to allow the chickens to run in and out. You can lift the back hatch to harvest eggs or clean out the coop.
A More Sophisticated Coop
The simple coop has a couple of problems. First, it is low to the ground; the chickens won't mind, but you will have a hard time harvesting eggs and cleaning it out. Second, it is not very secure against predators. A little more work can turn the basic coop into a chicken house.
Clear and level the ground as in Step 1 for the simple coop. Use cinder blocks to build a rectangular wall whose outside dimensions match the dimensions of the camper cover. Using premixed mortar mix, stick the blocks together, leaving a space for a human-size door and a place for a ventilating fan.
Place an inner row of cinder blocks around the inside base of the new structure. Place 2-by-4s across them, and top with a sheet of plywood. Make simple wooden boxes, and place them inside the coop for nest boxes.
Use some of the 2x4 stock to create a door frame that will be just level with the top of the blocks. Use some 1-inch planking or 3/4-inch plywood to create a door large enough for humans, and make a small, chicken-sized door in the bottom of the large one. Hang the door on the door frame, using the hinges.
Place the camper shell on top of this assemblage, and you have a tidy chicken house.
Fencing Around the Coop
Landscape logs make fine fence posts. Set them with 1/3 of their length in the ground at a reasonable distance from the chicken coop or house. Attach the woven wire to the outside, and line with poultry netting.
Make a small gate.
Cover the top of the enclosure with poultry netting.