I'm looking at the feasability of fitting an extra toilet in a large cupboard in our bungalow. It is against an outside wall, directly over the main sewer which is about 2metres down, with an inspection pit very close by. Does it need a vent stack pipe, and can this be outside? Also, does the waste pipe need taking down and sweeping into the discharge ( this would be difficult to achieve ) or can it discharge straight down, perhaps with a 45degree bend to direct effuent "downstream" ? Jeff