While you are thinking about vanity heights, also consider the height of your light switches and whether they will be horizontal or vertical
Metricon Liberty 45, Ryde NSW
http://forum.homeone.com.au/viewtopic.php?t=82846
That’s the same for us. Our experience was the the default height for light switches is quite low and is horizontal so that it is pretty much in line with the door handles. Apparently that is consistent with Australian and accessibility standards.
Metricon Liberty 45, Ryde NSW
http://forum.homeone.com.au/viewtopic.php?t=82846