Since I can find any information on the plumbing code, no standard in the Uniform Building Code Book. So I am unable to determine the location of the toilet supply valve. I assume that there is a standard by local of national standards as to the location. Any information is greatly appreciated.

Thank you,
GRH

The valve is normally located where the supply pipe comes through the floor or out of a wall and goes up to the toilet tank. Is there no pipe visible? Some commercial units have a valve that uses a special key. I have seen them in basements but that's not a good idea if you have a leak.

I rough in toilet supply seven inches to the left of the center of the toilet, and six inches up off rough floor. Some people do seven and seven. This is just what I was taught early on in my apprentice ship. I don't think there is a standard. Exact rough in from center to side will vary depending on the brand of toilet, but seven from side and six up works great for all toilets I have installed. Curious to hear what other plumbers in other areas rough in at. One thing to note on the height is what type of baseboard is going to be used. You want to make sure the rough in is high enough so the escutcheon will clear the baseboard, or if using a tall baseboard, low enough to fit completely within the baseboard. Hope that all makes sense. They make flexable toilet supplies in various lengths, so as long as your in the general area, you will be fine. And if your using rigid chrome supply, seven and six will put you close enough to easily bend the supply to fit. If your curious what the norm is in your area, just take a look at the toilets in other homes, and measure them up.

Sorry, I misread your question and thought you were looking for the valve.