In communities without running water, it's just good planning to dig the waste hole some distance from the home and cooking area. Why, then, do some Western homes have bathrooms next to the dining room and the kitchen? The answer is plumbing placement. Having a shared hot-water source between the kitchen and bath, as well as a means to have piping curve downward to eliminate wafting upward fumes, makes for an unusual proximity for eating, and well, eliminating. The bathroom itself can have its own problems, since the places you wash your body are right next to the toilet.
Choosing historic home living often means accepting that your dinner guests may be uncomfortable using your one and only bathroom until after the other guests have cleared from the table outside of the bathroom door.
Placement, arrangement and number of bathrooms are considerations for growing families, and accessibility can also be a factor for aging families. In a split-level home in particular, up- and downstairs mobility is important, as is getting children and parents off to school and work on time each morning.