We used the same wires as pauluk described, but until the late 50ies. In the 30ies insulation usually was rubber with cotton only wound tightly around the wire. When you start pulling on a single end you can rip down the whole covering. It was used for either surface mounted knob and tube wiring or directly put into plaster as far as I've seen. In the 60ies PVC insulation came up, either single wires in conduit or a special type of double sheathed zip cord, with more space between the conductors. still common, in Germany more than in Austria. Romex came up in the late 70ies or early 80ies, but had to be in conduit when put in plaster. Since the early 90ies it is common to put Romex directly into plaster or use flexible PVC conduit. In cellars or other damp locations the only way of wiring is still to put Romex in conduit.
To the differences between European and American building: I have been to the US only for short periods, but once I lived in an old house in NYC that was short before breakdown, there I had good possibility to study the inside of walls, ect. Furthermore I'm interested in international building, kinda hobby, so I searched the web.
Most meters are inside the house, another difference. Power is cheaper at night. We have different tariffs depending on the rating of the service. For instance there's one for small homes, one for bigger homes, one for small business,...
thanks for the comments, "blame" my teachers, I learnt it at school.
