AMAMI HOUSE

On Amami Ōshima, Kazunori Sakai has used his own family home to test a demanding proposition: can a house for four operate without grid electricity or air conditioning in a humid subtropical climate with limited solar yield? AMAMI HOUSE answers through vernacular intelligence, resource cycles and a social life as important as its energy performance.

Five separate volumes reinterpret the island’s buntō tradition, assigning functions such as sleeping, bathing and storage to distinct roofs. The spaces between them become the home’s generous shared rooms, extending towards verandas and gardens. Corrugated metal and irimoya-like profiles, deep eaves, layered insulation, raised construction and cross-ventilation temper sun, wind and sudden rain.

Self-sufficiency is embedded in daily routines. Construction offcuts fuel a wood-fired sauna; kitchen waste returns as compost; and garden produce comes back to the table. These are modest loops, but together they make consumption visible to the household and reduce dependence on distant systems.

The house remains open to the gatherings that define Amami as an “Island of Ties”. Sakai connects environmental autonomy with yui, the culture of mutual cooperation: resilience here does not mean retreating from neighbours, but creating a place capable of supporting them.

AMAMI HOUSE is strongest where environmental performance and spatial culture meet. Its five-volume arrangement uses separation to create shaded, ventilated in-between rooms, while deep eaves, raised construction and cross-ventilation respond directly to Amami Ōshima’s humid subtropical climate. The project treats self-sufficiency as a domestic practice rather than a technical display, linking energy, waste, food and social life within one coherent architectural system.

Off-grid houses are often narrated as feats of individual independence. AMAMI HOUSE offers the more relevant island argument: technical autonomy and social interdependence can reinforce one another. Its shared in-between spaces are as essential as its passive envelope.

The project is convincing because vernacular form has not been preserved as image. Buntō separation, deep eaves and raised floors are put back to work under current climatic and energy pressures. This is tradition used prospectively.

IMAGE 01 — FIVE-VOLUME COMPOSITION The project is organized as five separate roofed volumes, allowing the spaces between them to operate as shared living zones and climatic buffers.

IMAGE 02 — DEEP EAVES AND VERANDA EDGES Extended roof lines create shaded thresholds between interior rooms and the garden, moderating sun and sudden rain while supporting outdoor daily life.

IMAGE 03 — RAISED, VENTILATED LIVING SPACES Raised construction and cross-ventilation respond to the island’s humid subtropical climate without relying on air conditioning.

IMAGE 04 — MATERIAL AND RESOURCE CYCLES Timber, construction offcuts, composting and garden production form part of the house’s visible resource loop, connecting building, household and landscape.

IMAGE 05 — SHARED IN-BETWEEN ROOMS The gaps between enclosed volumes are treated as active rooms for family and community use, reinforcing the project’s relationship with Amami’s culture of yui.

The accessible editorial brief describes five function-specific volumes arranged to generate shared in-between spaces. Sleeping, bathing and storage are distributed under separate roofs, while circulation and communal life occupy the shaded gaps between them. This arrangement recalls the island’s buntō tradition while providing a contemporary environmental strategy: more perimeter for ventilation, deep eaves for solar and rain protection, and a close relationship between interior rooms, verandas and garden.

No complete dimensioned plan, section or area schedule is included in the accessible editorial brief used for this consolidation. The spatial reading above is therefore limited to the documented five-volume organization and the stated passive-design principles.

OFF-GRID HOUSE IN AMAMI ŌSHIMA When I began designing my own house in the center of Amami Ōshima, I never imagined it would eventually be disconnected from the power grid. Yet, as environmental degradation accelerates and extreme weather becomes the norm, that choice became inevitable. The decision was catalyzed by a mountain I purchased three years earlier—a place where I began developing my own micro-infrastructure to live independently, preparing for unforeseen crises while envisioning new forms of resilience in aging, depopulated regions. Implementing full self-sufficiency deep in the mountains proved difficult. The main challenge was the island’s surprisingly low solar irradiation—comparable to northern Japan. After evaluating wind, hydro, and geothermal power, solar energy remained the most practical option. To test its feasibility, I chose my own urban residence as an experimental site. Ten days before the groundbreaking ceremony, I decided to sever the connection to the national grid. The result is an autonomous, self-circulating house that allows a family of four to live comfortably without external electricity or air conditioning, even under Amami’s harsh subtropical conditions of high humidity and limited sunlight. Rooted in the island’s vernacular memory, the design reinterprets traditional spatial logics and crafts a contemporary way of coexisting with nature. Inspired by the region’s historical buntō (multi-volume) layout, the house consists of five independent volumes—each serving a distinct function such as bath, bedroom, and storage—arranged geometrically to create in-between spaces that serve as shared living areas. These connect fluidly to verandas and gardens, blurring the boundaries between inside and outside, family and community, human and nature. The roof form reinterprets the local corrugated-metal and irimoya profiles, integrating layers of insulation, ventilation, and light control to respond to Amami’s climate. Referencing the elevated takakura granaries, the structure allows wind to pass freely in all directions, while deep eaves moderate intense sunlight and sudden tropical downpours. A small wood-fired sauna uses fuel recycled from construction offcuts, creating a closed resource loop between builder and site. Food waste is composted and returned to the vegetable garden, where harvested produce re-enters the family’s daily meals—forming a living ecosystem of circular sustainability within the household. Amami is known as the “Island of Ties,” where communal rituals remain central to life. Family celebrations often gather over eighty relatives and neighbors, continuing late into the night. While such traditions have faded with urbanization and isolation, this house restores that cultural rhythm. The open, tolerant spaces naturally invite people to gather and share time together, blurring the distinction between private dwelling and communal place. This project redefines the contemporary home as both shelter and cultural platform—an architecture that sustains life beyond the grid while inheriting the spirit of yui (collective cooperation). By responding to the unique climate and cultural ecology of the southern islands, it quietly reexamines what it means to “inhabit” in the age of environmental uncertainty.