We've had our share of chicken tractors through the years. We started with the Salatin style. low to the ground models. The birds really didn't get a fair shake in them. Then we designed a multi-purpose, knock-down range shelter. The sides are panels made of hardware cloth that hook together. The roof is lightweight and easy to remove. This is a great day range house for meat birds, but not easily moved on a daily basis. When I saw this featured on craigslist for only $50, my heart skipped a beat.
This sturdy structure has plenty of practical features. A section of the roof lifts up so the loft and roosting area can be cleaned. There are two nesting places in the loft area at the back of the tractor. A handy lift up door on the outside allows me to reach in and gather the eggs. The little ladder is pretty cute, but my hens just jump up onto the roosts. There is even a heat lamp in the top. The only problem is I can't pull it. The man I bought it from mentioned putting skis on the bottom. Hmmmm. My son mentioned wheels on brackets could also easily be added. The good thing is that it is lightweight enough that it is easily moved sideways. I can even move it alone.
The boards along the outside edges are to keep the pesky skunk from digging in. He/she tries to dig in on a regular basis in its quest for eggs to eat.