I think he meant window frames, nobody expects glass. There are frames in the photos.
Personally I rarely add them to buildings, especially WWII buildings as I tend to do the insides fire blackened and I assume the window frames burnt or were takes for wood. I then got into the habit of not doing them on other buildings because I never really noticed they were missing. They tend to add a point of weakness to an otherwise sturdy gaming building.
No doubt dominic has different reasons though and it's his thread so I'll shut up. :lipps: