This stair is more like a room serving many different functions
I'm underwhelmed with the exterior of this house in South Korea designed by UTAA architects; it is all solid wall with slit windows because the clients were worried about privacy and people peeping through windows. So the architects developed a courtyard plan with most of the glazing opening inwards, an idea that has given people privacy and security since Roman times. We're supposed to be underwhelmed with the exterior, because that's not where the action is.
And indeed, inside there is a lot of action, taking place mostly on this wonderful stair that the architect says acts as a room rather than a stair, where you can read a book, watch a movie or play with the kids.
Courtyard plans make a great deal of sense; front yards are pretty useless wastes of space. You can get higher densities. People can leave their windows open at night without fear and take advantage of the stack effect to keep natural ventilation going. And you save on drapery.
If only the exterior didn't look so forbidding. More images at Archdaily. More on courtyard plans in related links below.