I've been trimming surplus building foam from around some gaps I filled, so I can get insulation panels cut and fitted. Then I had a -EUREKA- moment regarding my windows. It seems whatever I do I have something of a draft and one of the windows, the one that has been troublesome to work with, gave me an idea. I figured if I have a gap between the wood and the concrete - i.e. around the window frame rather than around the window - then that could explain why it seems so hard to beat the cold air.
To test it I've dealt with four windows so far. It's a bit of a drag getting the air compressor in there to blow out absolutely everything from the corners, then the shop vac to gather up all the crud, then repeat with the air compressor until nothing more comes out, then the foam gun just about reaches the far corners so I can fill all the corners with foam. Once the foam cures I'm planning to screw some pieces of wood in there for some extra strength, probably spray some more foam to fill odd gaps, and fill the remaining voids with fiberglass.
It's also a bit of a drag hauling a heavy air compressor, shop vac, separator, and all the assorted hoses and cables, but it's good to get a load of the crud cleared up and cleaned out. And I've filled most of a black sack ready to go out with the garbage, which is good. When I'm pulling down endless lath and plaster it goes into rubble sacks that end up taken to landfill but when it's small scraps of this and that, dust, the chippings from doing battle with walls, scraps of foam cut away and the like, it all goes in a black sack and the nice garbage men take it away. Which is good, because it gets rid of it so it's not in my way, and saves me having to take it to the landfill.