One of the most common mistakes I find while doing inspections is the location of the toilet tissue dispenser. Below I have referenced the most common dispensers used in toilet rooms and the requirements for each.
Single Roll Dispensers
Double Roll Dispensers
Double Roll Stacked Dispensers
Accessibility Standards Requires
The dispenser must be 7" min (180 mm) and 9" max (230 mm) in front of the water closet measured to the centerline of the dispenser.
The height measured to the outlet of the dispenser must be 15" min (380 mm) and 48" max (1220 mm) above the finish floor.
There is a construction tolerance built into the requirements. The accessibility standards requires when there is a min/max given that those dimensions must be met.
Single Roll Dispensers
The single roll dispenser must be measured from the center of the roll to the leading edge of the water closet.
The height must be measured from the finish floor to the bottom edge of a full roll of paper. Do not measure to the center of the spindle, that is not an outlet. Assume a toilet tissue roll is about 6" diameter, so give yourself a few inches from the center spindle. Some manufactures recommend 24" to the center of the spindle.
Double Roll Dispensers
The double roll dispenser must be measured to the center of the unit, not the first or the last roll. There is usually a mark on the top of the unit that will show the center.
The height must be measured to the dispenser outlet, which is usually at the bottom edge of the unit where the paper comes out. Also, most manufacturers recommend a dimension. Follow their recommendation, but make sure you meet the accessibility standards. I've seen some sites that reference the old standards.
Double Roll Stacked Dispensers
The height must be measured to the bottom of the lowest roll and the top roll is 1 1/2" min (38 mm) below the grab bar.
The manufacturers will recommend a height of these dispensers because they want to make sure you will be able to access the top seat cover dispenser. There are no requirements for the seat cover dispenser except that they must be within reach range.
Common Mistakes
Dispensers must be located in front of the water closet.
Movable dispensers are not allowed in accessible toilet rooms.
Dispensers are required to be mounted on the side wall.