#14038

Not sure if this is what you are looking for in terms of advice but this might help: In most cases, there is always a 100mm stack (pipe riser) and then it branches  into a smaller pipe, it is always good to try and work your layout around this pipe.

The only tricky bit is that by law you need a floor waste in the bathroom. This is difficult because it is the only pipe you need below floor level (and in a kitchen there is no such pipe). All the others are above ground so you can work around them.

If you cannot get a pipe below floor level , what can be done is that a dry floor waste be installed (not connected to sewer). Then this gets installed close to the outside wall ,which involves coring a hole from just below finished floor level. It goes out the wall to the outside.

The only time water will discharge through this is when there has been a flood in the bathroom. When doing it this way always need to remember to install a vermin proof flap.