Consider a Saniflo pumped waste system 320cm straight run to an outside wall.
- Suggested min fall is 1:200, so 1.6cm pipe fall.
- Proper min fall is 1:100, so 3.2cm pipe fall.
1948 concrete raft depth to rebar is probably at least 100mm re Asphalt, Screed, Concrete. So I do not need to consider batten/ insulation/chipboard the entire ground floor and packing stairs.
To bury a 2.2-2.8cm plastic coated copper pipe in such a floor at
3.2cm fall requires at least a 6cm deep trench (at deepest point).
Q - what is the min height above ground for a Boss Entry to a CI Soil Pipe?
I have 2, maybe 2.5, brick heights from floor surface to ground outside. I can not recall if a Boss Entry must be some min distance above ground, or their height.
Only the sink, rather than toilet, would actually see much use.
Alternative is just exiting the wall, dropping >=450mm with paving cover to a low depth brick manhole cover and do a low level side-entry angled to suit flow direction. That is not as pleasant a solution, although not an inappropriate backup from a "bypass-the-rest" view.