Sigrid,
Attached privies are not abnormal in rural villages and small towns here in
the East.  Many standing structures (like my house ca. 1830, and my neighbor's
ca. 1850) still have them -- though not fufilling original purpose.  I used
mine for awhile as a compost that could be accessed during the winter without
having to put on the boots.  Night wagons would come around to empty the
barrels on a regular schedule.  I could obtain some photos if this would help.
Douglas