Sa_Yu House / FATHOM

Architects: FATHOM
Area: 189 m²
Year: 2025
Photography: Tatsuya Tabii
Lead Architects: Hiroyuki Nakamoto
Architects Team: Hiroyuki Nakamoto, Naoki Itaya
Landscape Architecture: Hiroshi Nagao / Nagao Lab
Mechanical Engineering: Kengo Tanaka
Engineering & Consulting (Paint Works): Tatsugo Shono / Shono Paint Works
Manufacturers: FLOS / String Light Sphere Head, MARUNI / Lightwood Papercode
City: Kure
Country: Japan

Located on a sloped site in Kure City, Hiroshima Prefecture, Sa_Yu House by FATHOM reimagines domestic architecture through the overlapping of renovation and extension. The project transforms a 70-year-old timber dwelling into a sequence of spaces that mediate between past and future, private and communal. By dividing the house into distinct yet interconnected wings — the private, living-dining, concrete void, and community wing — FATHOM creates a dynamic balance between segmentation and connection. The project’s reinforced concrete void links the entrance and courtyard while acting as a vertical light well, softening the boundary between interior and exterior. A new steel-and-concrete community wing expands the home outward, forming a semi-public space integrated with the terrain. Through its material contrasts and adaptable spatial framework, Sa_Yu House reveals architecture as a living process — a continuous act of renewal in which life itself becomes an evolving design.

Sa_Yu House is conceived as an exploration of continuity and transformation. Situated on a hilly site in Kure, the project redefines the domestic condition by layering two temporal phases — the restoration of a wooden dwelling and the addition of a new communal volume. FATHOM’s design resists the linear notion of renovation; instead, it allows the old and new to coexist, their dialogue forming the foundation of a home that embraces both memory and change.

The renovation began with an act of observation. The architects studied the previous generations of extensions and repairs that had shaped the existing house, reading them as fragments of lived history. By dismantling selective portions, FATHOM revealed the structure’s latent order and inserted a reinforced concrete void that vertically connects the entrance with the courtyard. This insertion, both foreign and integral, transforms the dwelling from a static enclosure into a fluid organism of space, light, and air.

Within this reorganized plan, the house becomes a constellation of independent yet interlinked zones. The living-dining-kitchen wing, private wing, and community wing each assert distinct identities while maintaining a sensory continuity through materials and light. The concrete void serves as the mediating center, its diffused brightness drawing together the timber and steel elements that define the home’s new equilibrium.

The living-dining-kitchen wing serves as the domestic core where daily life is quietly re-edited. Here, appliances are clad in custom wood and steel panels, transforming utilitarian objects into architectural components. This integration minimizes visual noise and establishes a deliberate calm. Above the dining area, a single suspended light cable marks the passage between eras, bridging the warmth of old beams and the precision of new finishes.

Spatially, subtle level changes define atmosphere without physical boundaries. The slightly sunken living area invites occupants to sit along the floor edge, shifting their perspective toward the inner courtyard. Through this gesture, FATHOM achieves a sense of containment that remains porous, balancing intimacy with openness. Light and shadow intermingle to create a tranquil dialogue between interior depth and exterior brightness.

The RC void, positioned between wings, acts as both anchor and mediator. Its frameless skylights draw daylight through the concrete core, animating the walls with slow-moving patterns. A 65-millimeter-thick acrylic bench at the entrance captures these shifting rays, transforming the threshold into a moment of quiet reflection. Neither corridor nor courtyard, this space functions as a living margin, binding solitude and interaction within a single architectural breath.

Each boundary within Sa_Yu House remains intentionally flexible. Sliding partitions allow inhabitants to transform the house according to season or activity, blurring distinctions between interior and exterior. When opened, the courtyard and entrance merge with the communal areas, creating a spatial continuum. When closed, the home contracts, restoring privacy and stillness. This adaptability gives the architecture an organic rhythm that mirrors the pulse of daily life.

At the rear of the site, the new community wing extends the domestic landscape outward. Constructed from reinforced concrete and steel, it replaces an old barn while following the natural slope of the terrain. Excavated into a triangular plan, the semi-underground structure forms a stable base that anchors the house within its hillside context, merging architecture and topography into one continuous form.

Inside this extension, a long reception table and integrated benches emerge from the concrete wall, transforming functional elements into part of the building’s fabric. A spiral staircase ascends toward a two-story communal volume filled with diffused light. The space becomes an open framework for gatherings and workshops, blending social activity with architectural expression.

Externally, the community wing is clad in silver-painted fiber-cement panels whose seams remain deliberately exposed. Gutters are integrated within these joints, combining utility with refined detailing. As sunlight strikes the diagonal wall that bridges old and new, the façade subtly changes tone, reflecting weather and time. This dynamic surface allows the inorganic materiality of concrete to breathe within its natural context.

The private wing, in contrast, turns inward. Adjustable wooden louvers regulate light and view, filtering the landscape into patterns of shade and motion. Their slanted geometry echoes the angular wall of the new extension, visually linking the separate constructions. This repetition of oblique lines binds the building’s contrasting components into a unified whole, reinforcing the architectural theme of correspondence across eras.

Throughout Sa_Yu House, the interplay of material, proportion, and light establishes an architecture that accommodates evolution rather than permanence. The design suggests that a dwelling need not be static; instead, it can act as a framework that adapts to changing relationships and rhythms of life. Each space invites reinterpretation, allowing occupants to adjust boundaries and redefine intimacy.

By embracing both division and unity, FATHOM has created an architecture that extends beyond the domestic realm. Sa_Yu House is not simply a residence but an instrument for living — a structure that evolves through time and use. Through its calibrated layering of timber and concrete, openness and enclosure, the project expresses an enduring belief in architecture as an active participant in life’s continuous unfolding.