stuzzo:
The problem with poly is that it prevents vapour diffusing out of wall once it gets in which can lead to dampness and rot, especially when impermeable exterior linings such as XPS are used.
+1
We need to be careful when knocking NZ's building requirements by comparing them to overseas examples. Different environments (humidity levels/daily temperature swings etc) require different approaches, so whilst some concepts are readily transferable, others may be more specific to the local conditions than we initially think.
