WE have a basement bathroom where extra fixtures were clearly added, meaning it was I think just sink and toilet, and now there is also a shower. The sink has backflow. Eventually we will have to bust open the walls and look at the plumbing, but I suspect that the shower was put where once the sink was, and the sink was just tapped into the drain line, and there is no venting for that fixture, but who knows. Your town should in theory have checked that the venting was correct- there are certain constraints as to how far a vent can be from a fixture, and one would hope they would have caught an error there..... one would hope. But clearly a competent plumber would have to look at the planned plumbing layout and let you know if it was correct. Then hope that's what they actually did. In either event.... plumber needs to come back- they have some 'splaining to do!

My parents house is like that, but there’s a wall with a wide doorway into the area with the vanity, so it’s open but also easy to close off by just putting a curtain rail up. It’s also oriented to the room such that if you only use enough light at the vanity to wash your hands for a midnight potty run, it really isn’t enough to bother someone in the bed if you place the bed sensibly. Getting ready in the morning would be trickier if you needed to do makeup and so on so needed proper lighting, so that’s where a screen or a curtain would come in.

I'm on the peninsula too, and I doubt that the contractor can make any money at that price, especially if you chose nice fixtures. That bid probably assumes no change in plumbing and contractor grade fixtures and materials, so if you're not particular, or the house is a rental or something, it might be possible. I recently got a bid of 30K for a completely new bath in an older tract on the Peninsula. I did the room for around 15K, but I'm a designer living with an electrical contractor and we called in some favors and did much of the work ourselves. Of course it is quite luxurious..... As for the cultured stone, I did use it sparingly, with beautiful results as a deck around my soaking tub where real marble was impossible, but If you intend to use it entirely throughout the bathroom, have someone with a very good eye for color choose it. I could recommend a company on the peninsula, but I don't know if we're supposed to name businesses in this forum. Be careful. IMHO, one can easily cheapen the look of an otherwise nice bathroom with cultured stone. That's why people tear it out and replace it with tile. Kathryn

We are moving forward and will do the work ourselves if it comes to that. At this point the final configuration will be determined by the drains and vents required for a free standing tub, toilet and sink. As shown in the initial post, the existing constraints include log walls which cannot have any plumbing, a single internal wall which holds the vent stack that continues through the roof, maintaining entry and exit points for existing 3 inch line. I also plan to use the internal wall for the tub filler. All other plumbing will be in the existing crawl space which will require putting p traps for both the tub and the sink below the sub-floor (I know not allowed). The previous pedestal sink had the p trap below the sub-floor and we never had any problems. The entire crawl space is accessible and provide plenty of space for proper slope. The biggest challenge is venting each fixture. I really wanted to flip flop the vanity with the toilet but thought it would be really difficult to vent the toilet in that location. The design tool I am using wants to run horizontal vents to the stack. I'm sure this is not optimal. Also the tool refuses to run a vent to the sink. Our kitchen sink has an Air Admittance Valve which works well so I guess we could do the same but would prefer vent to the stack if possible. Any recommendations would be appreciated. Sorry if I don't have the all the proper terms down, hopefully the drawings make it understandable.