This is my chicken tractor experience. Will you be letting them out of it regularly? If so keep them in there and feeling safe for a few weeks. That way they come back to it when they get out. Make it Tall enough to walk in is a bonus. How do you plan to move it? Try to design so you don't have to pick up super high or some May try to dart out when moving. Try to have the feed and water mounted to the house so it moves with it. I had a gutter on my roof that fed into the watering bucket that reduced the amount I needed to fill it. I wish I would have known about copper pipes in water to prevent algae when I had mine. Ensure the eggs can be reached from outside and ideally eggs can be retrieved without opening up an escape hatch for the geese. Ensure the poop can be cleaned out easily if there are any catch spots. Determine the unevenness of your ground and pick the tires that work best for it. Air filled tires go flat. Free push mowers generally have acceptable tires. The store bought ones are junk. Having a live trap built into the cage like it is a way in ingave never done but I would do that next time. Possums, racoons, and others are always sniffing around for the feed or birds.