Thanks for the replies.
I'll check out the Polypipe gullies as suggested. I don't have an option but to put the waste pipe through the wall and then down so I'm not sure about the back inlet thing, I guess I'll just have to take a closer look at one.
Thinking about it I suppose a gully...
I am putting a 40mm pipe that takes the sink and washing machine through the kitchen wall and need to connect this to the foul drainage system.
I am in the lucky position of a new build house where the foul drain exiting the foundations is still visible. My question is whether I am obliged to...