A rather narrow plot, 12 m wide, which obviously generated a PUD, although it was a neighboring house.
There were not many solutions, a compact house with two facades (front-back) or with a semi-inner courtyard, which would bring more dynamism and light and fragment a massive volume.
The inner courtyard was preferred, without necessarily generating a functional scheme, being still the pretext for the location of the staircase.
It should be noted that this configuration of the house was generated by the relatively narrow terrain.
In the meantime, the owners bought the adjacent land and it would probably have been a different house on a larger plot.