Narrow city type site shape that can be said to be one of the best in Tokyo. It is a detached house for two couples who are required to meet all the conditions such as roads, frontage, terrain, and directions, and the restrictions imposed by them.
▼住宅概览，overall view ©Nobuaki Nakagawa
The client rarely (for our clients) wanted an ultra-closed space. On the other hand, there were also domestic demands for maximum volume on a limited small site. It becomes a jewel-like skeleton when restricted by roads and altitude and marked diagonal lines.
▼建筑呈现出由道路、层高以及对角线定义的宝石般的形态 ©Nobuaki Nakagawa
a jewel-like skeleton when restricted by roads and altitude and marked diagonal lines
▼一层门厅和自由空间，hall way and free space at the first level ©Nobuaki Nakagawa
▼走廊，corridor ©Nobuaki Nakagawa
▼平时用于支撑门窗的轻质基材作为建筑的支撑元素 ©Nobuaki Nakagawa
the weak material that normally only plays a role
as a base material that supports the sash supports the building
▼二层通往三层的楼梯，stair leading to the third level ©Nobuaki Nakagawa
▼顶层天窗，skylight ©Nobuaki Nakagawa
▼屋顶露台，terrace ©Nobuaki Nakagawa
▼卧室，bedroom ©Nobuaki Nakagawa
The volume of architecture is not just proportional to its size. According to the program, visually give space as much as possible on the first floor, depth on the second floor, and height on the third floor to connect all scenes continuously and bring depth to the architecture. Can you do it? Therefore, we tried to restrain members as much as possible by using steel frame and steel plate structure together. As a result, the weak material that normally only plays a role as a base material that supports the sash supports the building, the free outer wall peels off to the site boundary line to secure the width of the building, and a cantilever of 4.8 m is secured. This has been achieved, and it has become possible to reach a height that allows it to reach above the sky.
▼二层餐厨空间，kitchen and dining area ©Nobuaki Nakagawa
▼浴室，bathroom ©Nobuaki Nakagawa
Spiral stairs and voids arranged around each floor are connected by three-dimensional flow lines and visual lines, creating a deep space.
▼楼梯细节，spiral stairs ©Nobuaki Nakagawa
▼三层走廊，corridor on the third floor ©Nobuaki Nakagawa
Elastic FRP waterproof was used for the outer skin, aiming for seamless construction. I think that the volume of non-details expands this architecture sensually. It can be said that this architecture is the base point of modern urban housing in order to scoop up the equilibrium of dense cities.
▼街道视角，view from the street ©Nobuaki Nakagawa
▼一至三层平面图，floor plans ©I.R.A.
Building name: spiral
Design: Akinori Kaseya + Daisuke Tsunakawa/I.R.A.
Structure: Yasuhiro Kaneda/yasuhirokaneda STRUCTURE
Location: Higashimurayama, Tokyo
Main applications: Private housing
Main structure: Steel frame partly steel plate structure
Number of floors: 3 floors above ground
Site area: 48.49m²
Building area: 29.07m²
Total floor area: 73.48 m²
Construction: Ogawa Kyoritsu Construction Co., Ltd.
Completion: January 2018
Photo: Nobuaki Nakagawa