All new siding and painted. Built from scratch doors. I'll store logs in there that I get for turning purposes. As my turning blanks dwindle, I can go there and make more. At least that is the plan.
I don't think you would necessarily need a lot...mostly, just a way to control airflow through it, right? Maybe some kind of adjustable vents, side to side, or front to back? And then, maybe a hygrometer to keep an eye on the humidity. If you wanted to get fancy, you could link the vents to the humidity, and maybe even find one of those control boxes that can adjust something based on the humidity. I was looking into making a refrigerator kiln at one point, and you can find some pretty nice automated control systems for pretty cheap.