Hey, thanks for all the replies. And about opening the treehouse up, I don't know if I could do that without damaging the frame. Just the way it's put together we ribbed the tarp with braces that are further braced onto the walls (I did that so the tarp roof would withstand slightly higher winds and snow, considering you never know how saskatchewan will end up weather wise :P). However, I do have an opening on the south side of the house for the door, which actually opens up about half the side of the shorter ends. I was looking into it yesterday and I think it might even be able to get direct sunlight in there