Kenny Chaos has the right recommendations (insects & insulation) - I’d add “Home security” to the list. What you want to make is something like a milk-man door, where you can load wood from the outside, through a hatchway and into your house. Milkman doors were once standard design features in my neighborhood and our local historic commission does not allow them to be covered, despite the fact that nearly every house that has one has been burglarized at some time or another by little sized burgulars slipping through the milkman’s door. Something like a night deposit drawer at a local bank might work well. It could be made wide and deep enough to drop in 5-6 pieces of wood and unable to be opened to the outside more than 5-6 inches; or just enough to slip a single piece of split wood.