I am getting ready to pour the slab for a Garage\Guest House. This Guest house consists of a room with a Bathroom and Closet. This question is kind of double sided, Construction and plumbing, so I thought I would be safe and put it into Construction. I hope I am right. To Explain myself before I get to the Question.

I was planning on puring the whole concrete slab and then having a raised floor for the Bathroom so that I could have access to all of the plumbing, in case of a problem, as well as I am not exactly sure of how everything will be laid out right now.

1st of all is there any code preventing the Bathroom from being raised, compared to the Bedroom?

2nd would it be fine to have the plumbing go up on the outside of the building into a insulated box and into the wall where the raised floor would be? Or would it be better to have the sewer and water go through the concrete floor and come up into the Raised floor?

I hope these questions don't seem like no brainers. I am building this guest house/garage to see how much I could do by myself or have contracted when I do my house.

Any help to these questions would be great.
Thanks
Todd

your question concerning code issues and bathroom floors would only be enforced if there were some H/C issues, that's primarily for Commercial construction. Plumbing is a licensed trade, which requires a permit. I did not permit my bathroom construction, I self performed.

I would consider measurements and layout for installing the plumbing in the slab over running these lines outside of the building anyday. First thing to do is add the dimensions of the wall thickness be it 2X4 or 2X6, which typically is 3 1/2" or 5 1/2" thick add 1/2" for sheet rock then allow at least 1" for clearance between the lid of the reserve tank and the sheet rock. If you bought a new toilet it would come with a dimension installation guide. This will provide you with the correct dimensions for installing the flange. Also allow for the tile you are going to install you may need to raise the flange 3/8-1/2" so the tile will install under the flange ring. If your concern is that you may not have allowed enough, "margin of error" when installing the plumbing, you can always block out the concrete around the floor drain for the toilet in a manner to allow you to adjust the piping prior to placing the stool. Keep in mind that you should know the centering of the stool you want to install. Don't forget to install the vent piping to allow breathing for the sewerage piping. If you run your supply in the slab make sure you protect the piping whatever kind it is with a cheap foam insulation. Concrete has a way of piercing into the walls of piping.

Your sewer line must have a margin of fall. You can not install this line any higher than the toilet itself. It is a gravity system just like the supply although the supply has pressure the sewerage does not. Very important to note. If you are tying into existing sewer lines, make sure you have fall versus rise. If you have to elevate your bathroom floor to get fall then that answers your question about the elevated floor.

Question, while we are at it then. I am leaning not doing the raised floor, and just putting it under the slab, so here is a quick question. How far under the slab must the Sewer and Water be?

I did check on the sewer drop 1/4" for each foot I believe.
Thanks