The 1991 requirements allowed the sink to butt into the maneuvering space required for the toilet, but the 2010 update prohibits that, so older buildings often run into trouble. The toilet now has to be within a 60-inch clear space and the sink must be installed beyond that area.
Sinks are frequently too tall as well, especially base cabinet models.
Sinks are often installed higher than 34 inches.
Standard base cabinets are 36-inches high – you have to special order to get one that’s 34 inches high, so that’s a common problem.