kaniue architects wraps steel ramp around 15m high kugenuma-y house in japan

kaniue architects has built the kugenuma-y house near the sea in shonan, kanagawa prefacture, japan, as a 15-meter tall, reinforced concrete structure with a hot-dip galvanized steel ramp wrapped around it. neither an elevator nor a staircase, the 150-meter-long ramp is used by the residents to climb up the entire 15 meters, while it also allows them to look into every corner of the building. at the same time, the ramp acquires another role, acting as a scaffold that allows for the easy maintenance of the tall construction while reducing costs.

all images by koji fujii/ nacasa&partners inc.

following the client’s wish for a 15-meter high construction which they could climb up to, kaniue architects developed a powerful, rough, and yet lightweight architecture that embodies its owner’s lifestyle. simultaneously, a need for a strong enough building to survive the winds of its seaside location resulted in the building’s reinforced concrete frame. the hot-dip galvanized steel ramp that wraps around it reaches the entire height of the structure, providing access into every floor. additionally, it creates a constant connection between interior and exterior spaces, ultimately reaching the highest level, where an outdoor terrace is located.

the house’s façade is characterized by a rough outside wall complete with large floor-to-ceiling windows that have direct access to the ramp. in this case, the ramp acts as an expanded floor, a fence that blocks out sunlight, a handrail for safety, and a blindfold that blocks the line of sight from the ground. though normally the outer wall of a 15-meter-high building cannot be exposed, as it will deteriorate and shorten the life of the building, the ramp serves as a scaffold, which facilitates maintenance work while reducing its large costs.