fortress-like residential building with irregular green terraces stands out in tokyo

outdoor planted terraces become part of the building's everyday life, creating a spatial continuum of inside and outside.

sofia lekka angelopoulou October 11, 2021 4 min

AN OPEN AND GENEROUS HOUSE BY KOMPAS

‘ibis sendagaya’ by KOMPAS is a concrete residential building in tokyo resembling a fortress that stands out form the urban fabric thanks to its irregularly-stacked volumes and lush vegetation. located in a mixed use area in sendagaya, near the national stadium in tokyo, the project is composed of two floors of tenant spaces and the client’s two-story residence above them. generously planted terraces become a part of the building’s exterior, creating a spatial continuum of inside and outside that forms a ‘three-dimensional loop’ of the living spaces.

the main challenge of the project was how to accommodate comfortable residential environments and sufficiently profitable tenant spaces within the site constrains, which allowed only 160% of the maximum floor area ratio due to the narrow front street. ‘the client, a family of five who used to live in an ample detached house with a garden, had concerns about the spatial quality of their new house with less available floor area and in a denser neighbourhood,’ explains the hong kong and tokyo-based architectural design studio. ‘thus, we tried to make it as open and generous as possible by actively incorporating outdoor spaces, despite the difficult site constraints.’

fortress-like residential building with irregular green terraces stands out in tokyo - 1 images © vincent hecht | @vincenthecht.photography

DUPLEX RESIDENCE RISES HIGHER THAN NEIGHBORING ROOFS

led by mai komuro, KOMPAS performed an elaborate analysis and studies of the site’s conditions and limitations to make use of its full potential. despite the low floor area ratio allowance, the maximum building height of the site is defined at 20 meters if the volume is adapted to the complicated shadow calculation. however, most of the buildings nearby are kept lower than 10 meters to avoid extra code compliance processes. while the neighborhood is relatively dense on the street level for residential use, the architects found potential open voids to create comfortable environments above the surrounding low buildings. therefore, the concrete residential building was developed to be taller on the northern side, elevating the duplex residence higher than neighboring roofs while maximizing the building volume and capturing open views of the surroundings.

each level’s floor plate is uniquely skewed according to the shadow regulation, usages, spatial sequences, and vertical relationships. this stacking generates shading overhangs and various outdoor spaces such as external hallways and green terraces. the linear façades around the building’s slab volumes are wrapped by metal bands with repetitive vertical slats like louvers. their design comes from the positive interpretation of the code requirements forcing a vertical slats design on the rooftop balustrade to conform to the shadow regulation. fortress-like residential building with irregular green terraces stands out in tokyo - 2

through the fully openable sliding windows at each floor, both the living room and the hall can extend towards the planted terraces and become a part of the living spaces. beyond the clerestory window of the living room, a roof terrace spirals up to the wide slope covered by the artificial turf, resembling an exclusive playground almost floating over the sky. ‘besides joyful kids running around, light, air, view, and all the flow of life and nature circulate seamlessly throughout inside and outside,’ notes KOMPAS.‘this project is intended to suggest one way of the approach towards mixed-use development and living spaces in the urban context. at the same time we purely pursued the sort of abundant and enjoyable living spaces where we would almost feel envy the kids growing up there.’