I want to build a little "trappers' cabin" on my property to house all my hunting, fishing, and outdoor junk in one common organized place. I want an aquarium for live bait and a place to tie flies without my cat's help. My own private tiny sporting goods store with shelves, racks, and so on. It will get the clutter out of my house and workshops. If I move it can become an accessory dwelling unit.

My question is how much, if any, climate control do you think is necessary to properly store guns and ammo? Thanks.