Maximum run on 32mm waste is 1.7m
Thanks for replying.
I was aware of the 170cm restriction on 32mm waste pipe. On the original proposal, the 32mm pipe is 100cm inside the house and the vertical bit outside was 45cm so 145cm altogether, after this first 145cm the pipe then widened to 40mm for the remaining 2m to the hopper.
However, I am now going to go with this single pipe arrangement, like this now.
Because I've discoved there simply isn't enough room in the hopper for 3 separate pipes, so the shower and basin will have to go on the same pipe.
And I will use an anti vac trap on the basin to eliminate induced siphonage.