soil stack inside or out?

[vonspritz]

Hi guys
Are there any rules about whether a soil stack has to be inside or outside the house. This is on a new extension. Also, I'm putting in trench blocks and want to leave a gap for soil and waste pipes. do they have to exit through the wall above or below ground level?
thanks for any advice you can offer
Vonspritz

 

[hibeealex]

well the sensible thing would be to follow the drawings, though the stack could be internal or external, and if passing through blocks it should be linteled over for protection

 

[vonspritz]

Ah! sensible! If only!
I'm building the thing myself and don't have any drawings. Hence the need to ask seemingly inane questions of people such as yourself. I'm still not sure about what level to exit the pipes, or if it matters.
Thanks for all input!
vonspritz