Corridors

Corridors are invented in the 17th century. Before that, in the middle ages, and even during the Renaissance, there was virtually no privacy in daily life, especially when you're living in a castle/palace. A palace is just one room after another, same with a castle, so when you go from this end to that end of the building, you'll be traversing through other people's room.

• See Robin Evans' work: Robin Evans, Figures, Doors, and Passages.pdf
• See also The Myth About Corridors

the corridor was intended primarily to split those who served and those to be served so that a direct sequential access for the privileged family circle could be maintained while servants were consigned to a limited territory always adjacent to, but never within the house proper.

Also think about longhouse.

This is another example that illustrates how meager the concept of individual was before the end of the second axial age. Together with the destruction of the immanent, hierarchical, social and political structure of cosmos came the advent of individual human beings. […] The arrangement of rooms in its hierarchy and function was also still very much governed by this sequence of movement from one room to the next, and not by the corridor.

By the way, you won't be able to understand what Lampedusa was writing about in The Leopard if you always think of a mansion building with corridors but no enfilades; for enfilades, think about Vatican.

The rooms in the abandoned apartments had neither a definite layout nor a name. Like explorers of the New World, they baptized the spaces they crossed with names inspired by their joint discoveries. A vast bedroom, where the ghost of a bed adorned with a canopy and skeleton ostrich feathers stood, was remembered as "the feather room." A staircase with smooth, crumbling slate steps was named by Tancredi as “the staircase of the lucky slip.” Often, they lost their way in the labyrinth of twisting corridors, sudden turns, and whispered pauses. To reorient themselves, they leaned out of window frames stripped of their glass, seeking familiar angles of the courtyard or garden to determine which wing of the palace they were in. But at times, even that did not help. Some windows did not open onto the great courtyards but onto forgotten inner yards, places marked only by the corpse of a cat or the usual heap of spaghetti and tomato sauce—vomited or discarded. From another window, they might suddenly find themselves staring into the eyes of some pensioned-off old maidservant. […] (pp.183 onward)