So I am moving my bathroom from one part of the house to another. The place I'm moving it too has a drain that i can use for the bath and sink already in place. The new bathroom is going behind a converted garage and the only thing that is gonna be tough is getting that toilet drain roughed in. So.... I was thinking of just building up a subfloor and installing the drainage under that and putting the toilet drain out the rear wall and tapping into the waste line from there. My question is how much room do i need under the toilet for the 3" drain lines? At the point where the toilet is going in, I think I have about 7" to work with. Will that be enough? And when I get the drain to the outside wall, can I put a ninety degree bend there and then slope it? I haven't dug up the existing DWV yet, so I don't know how much depth I have to work with yet.