Fascinating pictures, Wales, the one showing the backless house particularly. Was that after an air raid, or was it because of an over-zealous builder, or just neglect?
If you go round the smaller towns in what was East Germany, you find many sites, now vacant, in rows of older buildings. It was often because the local authority wanted to move people to new estates outside thye old town (just like Brum), but once they did so, they left the building to rot.
Another common reason was that because although the state had power to take them over, they could hardly do so if the legal owners could not be traced, and after the war that was often the case - either killed, or emigrated. So the old buildings just stood and rotted. Nobody did a thing until they collapsed, when they cleared it up.
Peter