House in Nonakamachi

[Structure Underlying Structural Dynamics]
The House in Nonakamachi embodies a design philosophy the architect calls “structure underlying structural dynamics.” This begins with a modular system in which every member is a four-inch square, dissolving the conventional hierarchy of large and small beams in timber construction. The result is a hybrid of linear frames and solid elements that responds flexibly to its environment. This system created unplanned voids—like cracks in a concrete wall—that later became integrated into the design as spaces for utilities and built-ins. The adaptability extends to the roof, which unites four modules and employs diagonal braces to eliminate the need for a central column, producing a large, open space. (Shin Yokoo, OUVI)Located in the suburbs of Maebashi, the capital city of Gunma Prefecture in Japan, the House in Nonakamachi combines a single-family residence with a hair salon. Unlike houses in dense urban areas, its design was not dictated by proximity to neighbors. Instead, it takes advantage of the open rural setting, celebrating the vast sky and distant horizon. The structure is a rectangular volume measuring 14 meters wide by 3.6 meters deep, constructed entirely from 4-inch square timbers, with diagonal braces supporting the roof at the center of the second floor. Essential living functions and structural walls are concentrated along the north side, allowing the south side to open to the surrounding landscape through tall vertical windows.The generous setback allows sunlight streaming through the windows to filter down to the first floor via the louvered second-floor deck. Rather than sharply dividing indoors and outdoors, the aim was to create a space where their relationship shifts gradually with changes in weather and time. It is not defined by a single function; instead, it adapts to the residents’ moods and daily rhythms—like a cat moving with the sun from one resting spot to another—sometimes serving as a place to hang laundry, other times as a desk for work.When planning began, the project faced a global lumber shortage. Anticipating industry conditions, we avoided supply issues by using standardized 4-inch square timbers consistently throughout the building, from foundation to beams. This approach also produced a light, flexible structure that feels attuned to its surroundings. To ensure stability, the short sides of the building use double columns, and the central axis is widened by 303 millimeters to accommodate utilities and built-in elements. These gaps subtly divide the space, providing margins that allow residents’ lifestyles to unfold, while leaving room for future customization.