The design team at Nendo knew they’d need a way to connect the three generations—and eight cats—living inside a newly constructed home in the Shinjuku area of Tokyo, so they created an enormous staircase. Spanning from the outdoor garden to the third floor, the steel-and-concrete structure isn’t designed for climbing between floors but does serve as a multi-level garden area and space for the cats to lounge. It also conceals bathrooms and the staircase residents actually will use, while the white-paneled walls hold additional storage.
Aptly named Stairway House, the interruptive project juxtaposes connection and separation within one home, the design studio said in a statement.

A stairway and greenery gently connected the upper and lower floors along a diagonal line, creating a space where all three generations could take comfort in each other’s subtle presence. Not only does the stairway connect the interior to the yard, or bond one household to another, this structure aims to expand further out to join the environs and the city —connecting the road that extends southward on the ground level, and out into skylight through the toplight.