Well, if you're only going to be there for another year then you might want to just make do with what you've got. I assume you'll be taking the coop with you when you go. Just build a spacious run when you get there.
Or sell the dog pen and put the money toward the cost of supplies for a new...
Any particular reason you're choosing to block off the area under the coop? It looks like a perfect chicken hangout spot. Giving them access to that area would substantially increase the square footage available to them.