This was one of our Covid projects. Our friend Sarah gave us this idea. We have a 24 foot tall living room and wanted a way to reduce heat and cold transfer from inside to outside. In addition Kristen did not want to feel like she was living in a fish bowl at night and wanted to pull drapes over the windows.
The solution? Shower curtains joined at the tops and bottom to create a large panel and then adding heavy black out material to the back. Put up some stainless metal bars and attached them with stainless mounts. We decided to go into the perpendicular wall so that the curtains could be moved completely out of the window for maximum light and to better secure the bar to a second plane.