It will be a metal roof, and the roof will be easily accessible for future maintenance from the deck. My uncles is my builder, and he is getting custom made windows from a local place that makes them. They are double hung, vinyl clad just like you would use in a new house. The windows fit in a 36 inch wide opening and I have forgotten the height, but something like 45 inches. You can slide up the bottom or slide down the top. They will also tilt, but I have no use for that feature. I'm getting that just because that's how they make them.
The sheeting is treated plywood (copper azole CA-C) with a lifetime guarantee. I can't recall what he said the floor was, but it is something that he really likes for floors. I noticed when I walked on it that they it was super firm and didn't have any give. The ground floor is poured concrete.
There will be several ways to enter. The outside steps is one way. These steps will be enclosed and you will have to unlock a door to get on them. At the top of the steps there will be a door into the top level, and about the middle of the steps there will be a door into the middle floor.
Also at the ground, there will be an entry door and swinging doors for ATV entry (but I don't have an ATV).
There is a 3 foot square hole with a ladder that goes all the way from the ground floor to the top floor. The is in the southwest corner of the blind. A picture of the hole is shown below. The ladder is not installed yet.
The funny thing is that I'm building this as a secondary hunting place rather than my primary place. If I have a good buck to hunt on my other farm, I will likely be hunting there for several reasons. However, I will wear this place out during the spring turkey season, and I can see coming here frequently just to get away from the rat race. But, I could end up deer hunting here more than I think.