Privies attached to, or incorporated in, houses were not uncommon during
the nineteenth century, during the transition to indoor plumbing.
 
I know of two Delaware examples built during the twentieth century, of
privies on the back porches. You can't call them bathrooms by any stretch.
They were functionally privies without sinks. The fixtures were made
especially for this use, so they must have been fairly common. The toilets
were cast-iron, with flush valves and flappers not unlike the privies on
modern airliners. As you stood up, the seat would rise and somehow release
a valve that flushed the toilet and opened the flapper.
 
One of these, with which I am most familiar, was my grandfather's house,
built with central heat and indoor plumbing in 1914 in a rather nice
suburban setting. I remember that my grandmother always threw the washwater
down this toilet. The other example was two doors away from my present
residence and was in use as late as 1972.  Because they had neither tanks
nor traps filled with water, these cast iron toilets could be used in
unheated settings (pun intentional).
 
A friend of mine reports that her father objected to a toilet inside the
house, or in the room where he washed, because he did not believe the two
functions belonged together.
 
A. J. Downing's 1850 Architecture of Country Houses is silent on the
subject, although there are suspiciously unlabelled rooms on some of his
plans.
 
However, on the subject of indoor privies, see a book by Frank J. Scott,
1886, titled, "The Art of Beautifying Suburban Home Grounds of Small
Extent.
 
One plate shows a three-holer in the garden, with a "wash-room" behind the
kitchen in the main house. Another plan shows a bathtub and basin in a room
off the master bedroom, and a two-holer on the porch. Even at that
relatively late date, the toilet had not migrated indoors, and sometimes
the bathtub was found near the kitchen. Methinks this arrangement is a
holdover from the time when the bathing was a kitchen function. I do note
that the 1886 plans do not contain separate wash houses, even though
several plans feature discreetly hidden drying yards, where milady's
intimate apparel could be dried away from the prying eyes. In fact, the
privy locations were much more visible than the clotheslines!
 
Food for thought.
 
 
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Ned Heite, Camden, DE  http://home.dmv.com/~eheite/index.html