Though the site is exceedingly narrow, it is long and the architects used that as an asset to create privacy. The long facades of the house are solid black and windowless to restrict views into the interior. The short sides are outfitted with full-height windows that bring in natural light but these are protected with a one-story-high exterior wall just on the other side to make sure no one peeks in.
The main device that brings natural light into most of the house, however, is the central skylight that is placed over a painted white iron staircase that penetrates the entire volume of the house. Since the house is 4-stories high, the architects had to do some gymnastics to make sure that the light reaches all four floors. The balustrades of the staircase are purposefully minimal and spare to make sure they don’t block any light.
The ground floor is comprised of bathrooms, the garage and a traditional Japanese room lined with tatami mats. One the first floor, a double-height living room faces a window to create a feeling openness and spaciousness in contrast to the kitchen and dining area, which have lower ceilings to create a sense of intimacy. To save space in the small house, two sides of the living room have built-in bench seating, while the other wall has a built-in stepped unit which makes a desk and also shelves that continue to the raised level that leads to the kitchen. On the third floor are two bedrooms with different ceiling heights with one bedroom that opens out onto a secluded balcony. And on the very top of the house is a narrow loft space that serves as a study and opens out into the central staircase to take advantage of the natural light streaming in.