The clear floor space at bathtub or shower is the easiest way to
identify between unit Type 'B' Option 'A', and Type 'B' Option 'B'.
Notes
Every Type 'A' unit must have at least one accessible bathroom.
Where the unit has more than one toilet or bathing area, the
additional bathrooms are not required to include maneuvering
clearances for an accessible bathroom, but must include the blocking
or reinforcement in the walls to allow for the future installation
of grab bars and shower seat. Section 1003.11
In Type 'B' units, when there are multiple bathrooms in the unit,
Option A clearances would apply to all bathrooms within the unit. On
the other hand, if Option B was selected for a unit with multiple
bathrooms, the Option B provisions would apply to just one bathroom
in the unit. All bathrooms must provide blocking for the future
installation of grab bars. Once an option is chosen, the
requirements are exclusive, there can be no mixing between Option A
and Option B requirements within a unit. Section 1004.11