Japan architecture studio Sakai Architects designed this house on Amami Island, an island of extreme humidity and among the shortest hours of sunshine in Japan.

This off-grid residence enables a family of four to live comfortably without dependence on the electrical grid or air-conditioning.

The Amami Islands are a Japanese archipelago in the Satsunan Islands, which are part of the Ryukyu Islands, and are southwest of Kyushu. Administratively, the group belongs to Kagoshima Prefecture, Japan.

The design by Sakai Architects reinterprets vernacular wisdom: beneath a broad roof, detached volumes connect with gardens and verandas, forming porous spaces where indoors and outdoors, family and community, human life and natural cycles intersect. Daily living is supported by small-scale loops of energy and resources—solar power with storage, natural ventilation, passive shading, and water-use strategies. These resilient measures minimize environmental load while grounding the house in the island’s fragile ecology.

Beyond performance, it acts as a cultural and ecological commons, extending the private domain into a shared realm that sustains traditions, fosters resilience, and models regenerative ways of living. By turning insular marginality into opportunity, the project shows how architecture can address climate change and energy crises not through technology alone, but through everyday practices of circularity—a quiet yet radical vision for sustainable dwelling today.

Casa Amami por Sakai Architects. Fotografía por Toshihisa Ishii.

Amami House by Sakai Architects. Photograph by Toshihisa Ishii.

Project description by Sakai Architects

When I began designing my own house in the center of Amami Island, 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 ageing, 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.

Casa Amami por Sakai Architects. Fotografía por Toshihisa Ishii.
Amami House by Sakai Architects. Photograph by Toshihisa Ishii.

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.

Casa Amami por Sakai Architects. Fotografía por Toshihisa Ishii.
Amami House by Sakai Architects. Photograph by Toshihisa Ishii.

The roof form reinterprets the local corrugated-metal and irimoya (hip-and-grable roof) profiles, integrating layers of insulation, ventilation, and light control to respond to Amami's climate. Referencing the elevated takakura(raised granary) 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.

Casa Amami por Sakai Architects. Fotografía por Toshihisa Ishii.
Amami House by Sakai Architects. Photograph by Toshihisa Ishii.

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.

More information

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Architects
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Sakai Architects. Lead architect.- Kazunori Sakai.

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Collaborators
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Landscape Architecture.- Urata Garden Design.
Engineering & Consulting - Lighting.- Kazuhiko Hanai.
Engineering & Consulting - Structural.- Masayuki Takata.

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Builder Constructor
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Kawaguchi Construction Co.Ltd.

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Area
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Site Area.- 358.28 m².
Footprint Area.- 142.08m².
Total Area.- 119.24m².

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Dates
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Completion.- 08.2024.

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Venue / Location
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Amami Island, Kagoshima prefecture, Japan.

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Photography
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Sakai Architects is an architecture firm officially founded in 2014 in Kagoshima, Japan, though its origins trace back to earlier offices established by Atsumu Sakai in 1979. The firm focuses on architectural projects that respond to the climate, culture, and local context, with offices on Amami Island and in Kagoshima City.

Atsumu Sakai (酒井萃) was born in 1950 in Kagoshima, Japan. He graduated in architecture from Nihon University and worked at Nishimatsu Construction Co., Ltd. In 1979, he founded his own firm, which, after several name changes, became SAKAI ARCHITECTS Co., Ltd. in 2014. As founder and CEO, Sakai leads the firm's creative vision and oversees projects that combine climate-sensitive design with cultural context and everyday life.

Kazunori Sakai (酒井 一徳) was born in 1982 in Kagoshima, Japan. He graduated with a degree in architecture from Hiroshima University and earned a Master of Architecture (M.Arch) from the University of Florida, GSoA. He worked at Atelier TEKUTO and Sakai Architecture Office and was CEO of Shall We Design. Since 2014, he has been CEO and partner of Sakai Architects, contributing international experience and leadership in contemporary projects.

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Published on: January 6, 2026
Cite:
metalocus, ANTONIO GRAS
"Off-grid residence. Amami House by Sakai Architects" METALOCUS. Accessed
<https://www.metalocus.es/en/news/grid-residence-amami-house-sakai-architects> ISSN 1139-6415
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