Hi, My coop was once an open air dog house. Approx. size 6x14 ft.. no floor and no roof. Just 2x4 frame with heavy 2x3 wire mesh around. Run totally enclosed with wire to keep all my predators out. I have been using this for 20 yrs. . But my girls are happy & give me eggs daily for my family & to sell. I would use what you have and build as you go!!!!!!!!!!! Wallygator