In Group 1 dwelling units, (see 521 CMR 9.2, Applicability) bathrooms and half bathrooms shall comply with the following:
bathroom is a captive bathroom ( a bathroom only entered through a bedroom) then both must comply unless the captive bathroom has two entries, one from the bedroom and one from the corridor, then only the captive bathroom is required to comply. If two common bathrooms are provided, then only one full bathroom must comply. If two captive bathrooms are provided, then both must comply.
521 CMR, § 42.1