In process of starting to build a house, been to prestart a few weeks back.
Already having problems with my builder regarding going hobless showers so I did some research on rules and regulations and asked a couple of plumbers regarding this and got a quote for a reflux valve. Thought I should make a post about it because my builder is trying to rip me off and hope this helps other people who are in the same situation.
Firstly, yes if you go hobless shower you have to install a reflux valve to your main sever connection to prevent back-flow of sewage from the main line in the street if there is a blockage. The cost of the valve it self is $320 inc GST from Reece plumbing and this is retail price.
There is nothing hard about installing it, it's joints are made from normal PVC piping and gets easily glued to the main sewage pipe between the house and the main line in the street. You only need one of these valves per house hold and not per shower like my builder is trying to convince me.
This sort of thing should not cost thousands of $$ to do so if your builder is telling you something different they are trying to rip you off.
My builder wants $2000 per shower and I have 2.