Why there is no single number
The Standards name toilet paper dispensers in 604.7 and sanitary napkin disposal units in 604.3.2, but a seat cover dispenser never appears by name. What covers it is the definition of an operable part in Section 106.5: a component used to insert or withdraw objects. Pulling a cover out of the unit is exactly that.
Section 205.1 sends every operable part in an accessible room to Section 309, and 309.3 sends its height to the reach ranges in Section 308. For an unobstructed forward or side reach, the point where a user takes hold of the cover must sit between 15 in. and 48 in. above the finish floor. The top of the cabinet can be higher; the rule measures the reach, not the housing.
Reaching over the water closet
A dispenser centered on the rear wall above the tank is reached over an obstruction. Section 308.2.2 then limits the high reach to 48 in. where the reach depth is 20 in. or less, and to 44 in. where the reach depth exceeds 20 in., with 25 in. as the deepest reach allowed. Measure the depth from the front of whatever is in the way to the face of the dispenser.
A unit on the side wall or the partition beside the water closet avoids the question, because the approach is a side reach from the seat. That is also where the dual-access units that serve two compartments through one partition are mounted.
Sharing the wall with the rear grab bar
Section 604.3.2 allows a dispenser to overlap the clearance around the water closet, so the rear wall is open to it. The rear grab bar is not. Under 609.3, anything mounted above the bar needs 12 in. of clear space, and anything below it or past its ends needs 1½ in.
With the bar top at 33 to 36 in. under 609.4, a dispenser above it starts a full 12 in. higher than that, and its covers still have to be reachable at 48 in. maximum. That leaves little or nothing to work with, which is why most layouts put the seat cover dispenser on the side wall or partition, or under the rear bar with the 1½ in. gap.
Choosing a seat cover dispenser
Read the spec sheet for where the covers pull from, since that point is what the reach range measures. Recessed and semi-recessed models keep the projection within the 4 in. limit of 307.2 wherever the unit stands in a circulation path; a surface-mounted unit is fine on a wall or partition inside the compartment.
The covers should pull free with one hand, without pinching or wrist twisting and with no more than 5 pounds of force, to satisfy 309.4. Keep a 30 by 48 in. clear floor space in front of or beside the unit under 305.3; inside the stall, the water closet clearance supplies it.
