This is our mobile coop build from plans bought from mobilecoops.com. It can be used as a tractor with no bottom, but for ease of movement and less wear and tear on the yard, we put a hardware cloth bottom on it.
Dimensions are 5.5ft tall x 7ft long x 3.5 ft wide. Weight is HEAVY but can be moved with a little muscle. Or you can add a trailer hitch and move with riding mower/ATV.