Villa Boso – Zero-Concrete Architecture
Villa Boso is a private residence located on a mountain ridge overlooking the Pacific Ocean on Japan's Boso Peninsula. The project is conceived as an exploration of Zero-Concrete Architecture, questioning the assumption that contemporary construction must rely on reinforced concrete.
Vernacular architecture historically developed without concrete, shaped instead by local materials, gravity, climate, and craft. This project revisits that lineage in a contemporary context by engaging directly with the land's geological condition. Geological surveys revealed that beneath the artificially modified surface lies an exceptionally stable Pleistocene mudstone layer—an ancient mountain surface formed more than two million years ago, now buried deep underground.
Rather than relying on existing concrete retaining walls constructed decades earlier, the building's foundation reaches directly to this geological layer. Small-diameter steel pipe piles are rotary-pressed approximately seven meters down into the Pleistocene mudstone, allowing the structure to stand—quite literally—on a two-million-year-old geological surface. This process requires no excavation and no concrete, resulting in a minimal and reversible intervention.
A contemporary timber structure rests on exposed steel pile heads, forming a stilt-like system that lightly hovers above the terrain. This approach reinterprets traditional Japanese construction, where wooden buildings were placed gently on stone foundations. Throughout the project, only recyclable steel and wood are used for the primary structure.
The elevated floor enhances long-distance views, privacy, and natural ventilation while protecting the building from the region's humidity. A simple gabled roof encloses an interior defined by a cycloid-curved ceiling. White silica sand finishes diffuse daylight, allowing subtle shifts in light to animate the space while keeping the surrounding landscape visually dominant.
The entrance hall is finished with traditional Japanese earthen walls made from local soil mixed with hemp fiber, hand-scratched to reveal a rough, tactile surface. In the bathroom, Towada stone sourced from northern Japan is used; its surface turns a deep blue when wet, quietly registering water, light, and time through daily use.
Material selection prioritizes local and renewable resources. Chestnut wood joinery treated with iron mordant improves resistance to moisture and insects, while floors are finished with naturally oiled Japanese chestnut. Walls incorporate diatomaceous earth, persimmon tannin, and eggshells, and insulation is made from reused wood fiber. The exterior employs traditional cedar board-and-batten siding and wooden storm shutters crafted by local carpenters.
By eliminating concrete entirely, Villa Boso proposes Zero-Concrete Architecture as a contemporary vernacular position—one that aligns architecture with geological time, local material intelligence, and environmental restraint.
Standing on this site for the first time, facing an ancient landscape untouched since geological time, the aspiration emerged: to conceive architecture within this eternal flow of time.
