Open, it is 12x12 feet. My somewhat unoriginal name for it was the Hastings Lake Observatory. Here are some pictures of the finished product. Click on an image to see a larger view. The Angus Smyth Telescope.
Frame's up, floor's on, hinged front wall is on.
Time to see if the scope fits. Closeup of fold down front wall with roof attached. Cable attached to middle of strut is part of counterbalance system. Line attached to top of strut is for pulling up and easing down the wall. The wall has a 2x8 outer frame.