I'm remodeling a lower level bathroom and it turned into more of a putting a new bathroom in. The bathroom originally had the bathtub and toilet raised off the floor for plumbing which was sloppy but I removed that and am going to put the plumbing under the concrete floor. I've included a drawing of what I would like to do in hopes that it helps. The sewer line is cast iron and as far as I can gather I can change this over to PVC in KY. I plan on a no hub boot for this connection since it will be buried and running horizontal. The line is about 3ft underground and the first connection would be the shower via a wye. I'll use 2" and vent it in the method I show in the drawing with 2". The vent will run up about 8' and then across the room to connect to the other vents that will run up to the attic and tie into the stack. The toilet will connect from a wye on its side up stream of where the show will make the connection. I'm not real sure how to vent this. I figure I'll vent out of the back of it but that would require me to run the vent around the sink's drain but it seems like it should work. Again this is a 2" vent tying into the others. The washer and sink are pretty much the way I found them but not sure who installed it. From my drawing what changes do I need to make. Any hints/help will be greatly appreciated!