Anglo Saxon Windows
Photo borrowed from this article about Anglo Saxon Churches.
And a quote from lower down *the same page as this photo* - and phrased, I thought, somewhat emphatically given that it is talking about a period over a thousand years ago, where the vast majority of the buildings that were standing then, are standing no longer.
"there are NO pointed arches from the Anglo-Saxon and Norman periods: they simply did not exist."
The reason I found this article was that I was trying to work out why all the descriptions of early Anglo Saxon houses are emphatic that they had no windows. I still can't figure this out. OK, no window glass. But lack of glass surely does not mean lack of windows. So far as I can see, all the evidence of Anglo Saxon houses that exists is pretty much holes with post-holes in them, and clearly they did know about windows in churches...
I looked at a bunch of reconstructions. So far, all the ones I've found either have very dodgy-looking walls, so that lots of light comes through the chinks (brrr!) or they have left half a wall off so that people inside can see what they are doing. Neither of these strike me as likely solutions. A 'weaving-shed' where you can't actually see your loom seems impractical.