You do relatively commonly see wastewater piping on the outside of a house in the UK, especially older stock (soil stack from the toilet, waste pipe from sink or bath running into it). This is fine in the UK climate where a normally empty pipe doesn't need insulation. I hear that it won't work in places that get extreme low winter temperatures, but the UK doesn't have winters that cold.

You don't see them on new builds, I think, probably because the pipe going from inside to outside would reduce insulation effectiveness.