The question is in reference to:
Where NFPA 13 systems are installed in residential applications, sprinklers can be omitted from bathrooms that do not exceed 55 square feet (5.1 square meters) in area as long as the walls and ceiling provide a 15-minute thermal barrier.
a sprinkler coverage in the bathroom wouldn't be able to reach a walk in shower enclosure (thats floor to ceiling enclosed). So technically, that would be referred to as a separate room in the bathroom? If so, would the 55 sf requirement only refer to the area of the bathroom less the walk in shower enclosure?