My grandparents have a two bedroom, two bathroom house in El Dorado County that was built in ~1974. One day I noticed something peculiar: while the two bathrooms were connected by a sliding door, you had to go through a bedroom to get to a bathroom.
Years later (around 2010) I was telling a friend about the aforementioned bedroom bathroom linkage and they said that's not allowed in today's building code so you could not get a permit to build a new house with that type of design. The person who told me this was not a contractor or anything related (and neither am I) so I never knew if that was/is actually true.
I just spent some time searching for this information out of curiosity and while it may exist on a page somewhere, I couldn't figure what to tell google to get me there.
I'm interested if anyone knows the correct answer here but I'm also wondering why such a requirement/restriction was added to the building code. And does the same rule(s) apply for a remodel, ie. could you change whatever design you currently have to one where you could only go through a bedroom to get to a bathroom? Not that you'd necessarily want to do that, but since we're on the topic… (~:
Best Answer
No, that is totally untrue. There are plenty of rules for bathrooms, but what you are describing would make all "master bathrooms" that are only accessible from the master bedroom illegal, and that is definitely NOT the case. And it is perfectly legal to have two "master bedrooms" in a house, in fact it is becoming a desirable feature on smaller houses because of the proliferation of shared housing.
Now, if you don't have a bathroom accessible from the general living area it means all of your guests must go through a bedroom to use the bathroom, something that I personally would not want. But that is not codified anywhere.