Last night, I opened all four windows in my bedroom to the crisp September night, tree frogs and crickets still in concert below, temperatures paused at 56 degrees. There are two sets of single pane French doors, just five feet tall, under the east-facing eaves on the second floor of the room in this old house, and two more windows on the west wall. Not a huge space, just generous enough to feel like a summer porch or a tree house, when everything is wide open.