HOUSE IN KIYAMA

A yellow-beige exterior sits quietly on a verdant hillside—an RC second house designed to capitalize on the level differences of its surroundings. The site lies between a frontage road positioned lower than the plot and an adjacent property with a drop of approximately 4.5 meters. Originally at roughly the midpoint between these two levels, the client chose this location—easily accessible from the neighboring site where their parents live—to build a new second house intended also for guests. The client brief called for a “one-room” setting somewhere between a residence and a hotel, along with garage functions for cars and motorcycles. Given the area’s high humidity, the design proceeded with careful attention to both site constraints and environmental requirements.

The architecture is composed through a rational combination of three primary elements. The first is a garage level accessible from the front road. The second is the living–dining level placed above it. The third is a generous slab that forms the terrace for the residential volume, functioning as a circulation link between the neighboring property and the house.

On the first level, a parking space occupies the front, with an area for motorcycles positioned behind. By adopting a skip-floor configuration, the necessary functions are accommodated with minimal excavation relative to the existing terrain. The second level follows the same logic: a height difference of about one meter is introduced between the living area and the dining kitchen. This allows zones to be defined without partitions, fulfilling the client’s request for a large, open one-room space. The slab described above serves as a spacious terrace and approach, while also acting as the roof of a dry area on the first level, creating a semi-outdoor space. Its tip is structurally separated from the retaining wall on the adjacent site and cantilevered to secure a ventilation route as a countermeasure against humidity. At the same time, this avoids structural complications that could arise if the building and retaining wall were integrated.

Because interventions to the neighboring site were possible in parallel with this project, the landscape plan leverages existing plantings and the site’s slope to form a cohesive environment continuous with its surroundings. The building’s volumetric composition also considers its relationship to the adjacent structure, with mutual sightlines carefully studied. Inside, a large opening is placed on the north side—where much of the existing greenery remains—to bring in stable light and verdant views throughout the day. In response to the exterior’s earth-like yellow-beige finish, the interior uses materials such as walnut and granite to create a calm atmosphere, while walls are finished in white to display the client’s art collection, introducing a measured contrast across the space.