We are planning to convert a half bath in a Manhattan multiple dwelling condominium to a full bath. We are not permitted to drill in to the floors. So, all of the piping will go through the walls and all 3 pieces (sink, toilet and bathtub) will funnel to a single drain which is currently the drain for the toilet. That drain will be underneath the bathtub. The toilet will be moved to a new location in the bathroom and we will be using a back/rear outlet toilet. The piping for the back/rear outlet toilet will need to be run underneath the bathtub to the drain. I believe that the pipe is 5.5 inches in diameter. My question is whether there is a raised outlet bathtub that will provide enough clearance to run the pipe from the back outlet toilet. I found a bathtub from Bootz Industries that has a 3 inch raised outlet. Was wondering if anyone is aware of a bathtub that provides more clearance. We're not interested in a free-standing bathtub on stilts that can't be used in connection with a shower.