I started building the base for a chicken tractor back in August 2017 while my wife was on maternity leave.... needless to say it was a busy time so it was delayed until November. My original plan was to put it on wheels but I decided skids would be easier and less expensive. The base is cedar but knowing it wouldn't hold up to dragging i put the base on treated 4x6's. The walls are normal stick framing and the building is sided in cedar shake panels(they were free!). I'm still deciding on nest boxes but due to how narrow the tractor is I'm thinking of going with some wall mounted roll outs. It is such a relief to have it mostly done and have all the girls out on grass.