Window frame detail
Here's a quick look at the frame in close up...
you can see the seat shape on both sides of the frame - this is to accommodate the window on the inside and the shutter on the outside.
Shutter will open out 180 degrees to sit flush against the wall. when closed in will follow the face of the wall, without protrusion.
The actual glazed window will be closed a lot of the time , but if needed can be opened to allow free air movement