Here's what I put together this year. I used the lower frame from a duck blind that I had been using the past couple of years in Oklahoma. The blind was made so each panel could be carried out and bolted together. I used the same concept with the deer stand.
I started with framing the floor so that about 1 1/2" of plywood overhangs the 2x6. I then built the sides and front/back so that the plywood overhang by a few inches. This way it was easy to push/pull the sides so everything was flush. I drilled 3 holes on the bottom 2x4s of the 8'ft front/back pieces and 2 holes on the sides. I could then bolt all 4 pieces to the floor. I also drilled the corners of the 1x4s so that I could just slide in a bolt to hold the 4 sides together.
Then I drilled the plywood on the sides and the 2x4's on the upper sections (with the windows), two holes on each side and bolted them together.
Then I simply laid the roof on the top and put a screw in each corner. From here I put the 2x2 tubing flush against the 2x4's on the sides and front/back and then screwed them to the roof.
I then disassembled everything and painted. I had to remove 6 screws from the 2x2 and 2x4's on the roof frame, and then the bolts holding everything together. Took about 15 minutes. Kids were disappointed to see the "clubhouse" go.
While the paint was drying I built the lower frame. Notched out a 2x12 so it fit right between the 2x6's on the floor. I bolted to 4x4s and cut the tops so they were flush with the notch. After everything was squared away I added the bottom brace. I did both sides like this and then bolted the 2x12 to the 2x4 (wish I would have put a 2x6 there, but was initially a duck blind and was just working with what I had. I then added my 2x4 diagonals to both saides and flipped her over.
Was really steady but was worried I would have a hard time getting all the panels up by myself, so I ended up cutting the 8' 4x4's down to 6.5'. Wish I would have left them.
I was able to fit everything in the back of my pickup. When I got to my location, just lined up the holes and put a few bolts in. After everything was bolted together I reinforced it with a few screws. If I need to move it, I can have it disassembled in about 30 minutes and loaded in a pickup.
Its not fancy and it does stick out a little bit. But it certainly got the job done. You can take a different approach with the windows and maybe use plexiglass so you can leave the windows closed and still see.
I went with 4x8 because I just felt it would be easier to build since the sheets already come 8 ft long. So its not anymore expensive and you can save on cutting.