We used four very tall (5.5') windows for the sides and door and two smaller windows for the roof. We framed it in on the inside, added two handles on two sides for moving about the yard, and two iron shelf brackets at the peak of the roof for a little character and added support. Isn't this just the neatest greenhouse - we call it our phone booth and even added a pay phone for even more uniqueness. I plan to really start my plants in it next spring.