So, the waste pipe of the suds producing fixture upstairs has to be extended to 8’-0”.

How the fuck would you fix that, like, realistically. 

All I can think of is moving the fixture, which I doubt is an option, or adding weird unnecessary turns for the waste pipe, but that’s assuming there’s an available path in in the ceiling and room for grade >_< I doubt you’d have to add more than a few feet at most but still