Example of what I'm talking about. First picture not sheltered, second sheltered, just by adding a beam along the bottom of the window because of the 1m height shelter check:

https://steamcommunity.com/sharedfiles/filedetails/?id=2442588098
https://steamcommunity.com/sharedfiles/filedetails/?id=2442588120

Using this you can make wide open shelters. Remember a beam/obstacle always needs to be at 1M height. Half wallls do not count. Vertical beams do not count.:

https://steamcommunity.com/sharedfiles/filedetails/?id=2442562719
https://steamcommunity.com/sharedfiles/filedetails/?id=2442562766