Stud wall and soil pipe boxing

[Mikie]

I have an alcove in the bathroom on wall adjoining a bedroom. This creates a step in the wall on the bedroom side that I'd like to eliminate.

I've realised that the alcove wall is the original house wall (plaster and lathe) and that the reason for the alcove was to box in the soil and pipes and cistern for the toilet and basin, and to allow for boxing in the soil from the toilet in the loft bathroom (2 storey 3 bed semi with loft conversion). The bedroom wall steps towards the bathroom, new stud wall, where there is no soil piping at ceiling level.

I want to take the alcove space from the bathroom and give it to the bedroom, eliminating the kink in the wall.
Its a non-load bearing wall, to my knowledge as the loft conversion steels will be taking the load of the rooms above.
I've seen in-wall cistern systems that show the soil pipe boxed within the wall which would be ideal for the bathroom toilet.

My questions are:
am I ok to box the loft soil pipe into the stud wall? Assuming that the stud wall depth would need to be sufficient to hide the pipe.
Does the ceiling level soil pipe run need to be accessible? (the current boxing isn't obviously dismantle-able)

Ta in advance
M.

 

[AWheating]

the pipe can be inside the wall, you may want to lagg it to stop any noise from what comes down it. the only thing that needs to be accessible and ventilated really is any auto air valve/ durgo if there is one fitted and any rodding access points.