Originally Posted by hanco
I like them 4 foot by 4 foot by 7 foot high. I like to be able to look out all 4 sides without moving my chair. I can see 3 sides turning my head, turn chair 1/4 turn to see the other

This!

I built mine 4x4 and tall enough to stand up to stretch from time to time, perfect size for one hunter shooting out all windows with just a swivel chair, also fit my sons when they were younger but was tight. Also, making them 4x4 save is wood expense and 4x6, 5x5 etc goes up exponentially with wood prices being what they and 4x8 plywood being standard. If I were just building one today, I might make it 4x6 but not sure.