This is my coop and the attached pen. My chicks are free range but they also have the pen for outdoor activity and that is what i open and close in the moning and at night. I have attached it to the side f my barn and stained the outside to match. The inside is insulated 2x4 wall with thin osb on the interior. The coop you see in the pen area was my first coop and they still like to go underneath it and dig in the dry dirt so i left it in there for them.