我孫子の曲屋根 Hyperbolic Paraboloid in Abiko

しなやかな木架構が覆う住まい A home covered with a supple timber structure

The curved roof floats lightly in the wind blowing from the lake below.

Facade created by the horizontal floor, curved roof, and continuous windows

Verandah that surrounds the entire perimeter and eaves that gradually change in height





It is a one-story timber structure house built in a residential area in Abiko City. Since the building is located on a hill overlooking Lake Teganuma, a popular local landmark with a great view, we designed the roof to be light and airy, resembling a sail waving in the wind. At the same time, we aimed to respond to the non-characteristic landscape created by the diverse colors and shapes of roofs that spread across suburban residential areas.

The gently undulating large roof appears on the ceiling inside the building and under the eaves in the semi-outdoor area. Places that are slightly low and give a sense of darkness, and places that open high toward the sky create a gradation of unevenness in the environment. In addition, by creating openings around the entire perimeter, the differences in direction and changes in time are combined, allowing spaces of various qualities to coexist.

The floor plan is almost a one-room space, with water areas and storage areas placed in the center, and living rooms arranged around the perimeter to allow for circular movement. The closer you get to the periphery, the more you can feel the difference in ceiling height, giving you a different sense of scale. The outside verandah further enhances the ability to move around and at the same time allows access to all living rooms from the outside. Functional redundancy was created because the interior of the room had no hierarchy and was treated equally to the exterior. Even if your lifestyle or how you use each room changes in the future, it will be possible to flexibly accommodate a variety of living styles. For the time being, one corner of the house is used as a workplace and is only accessed from outside, but the interior is connected under one roof, creating a coexistence of closeness and distance within the house.

The approximately 12m square roof is made of wooden frames with an HP curved surface (a type of shell created by arranging a hyperbolic surface, straight members and twisting the entire structure). By stretching orthogonal beams with a twist and placing roofing boards along the curved surface, a construction method that takes advantage of the softness that can only be achieved with wooden construction was used to create a flowing wooden frame inside. This house is also the atelier (workplace) and home of the structural engineer whom we designed with. Therefore, we aimed for the strength and delicacy of the frame, its softness and hardness, and the dynamic and immobile dynamics to coexist throughout the space.

Entrance Doma (Earth floor) connected to the outside

Continuous curved ceiling from the entrance to the living room

Dining kitchen with vaulted ceiling

Flat curtain design that wraps around the window all around

Large air volume created by the curved ceiling surface

Roof frame that brings gradational changes to the grid plan

Bedroom1 with a low ceiling that creates a calm atmosphere

Walk-in-closet that separates the living room and bedroom

Bedroom2 under loft

Atelier with high-ceiling posisionned diagonally from the living room

Facade (Evening view)

Original designed tussel for curtains

Timber frame under construction

Structural engineer (Naotake Koyama, left) and Architect (Akio Takatsuka, right)

(Photography : Hiroyuki Hirai, Aaat)