My understanding is that the standard toilet rough-in is 12 inches, and I understand that to mean that there should be 12 inches from the middle of the floor flange to the front face of the studs. Is that correct? My building has plaster walls, and I often find them to be over 3/4 inch thick, and I often find that the toilet floor flange is set too close to the wall anyhow. Does anyone know if there are any commonly available toilets that are designed for a 10 inch rough-in, or that are designed for a 12 inch rough-in but leave plenty of room behind the tank? I'm trying to solve this problem before I'm staring it in the face. I want to find a replacement toilet I can use if a toilet gets damaged and I have to replace it.