Amami House Casa by Kazunori Sakai is a highly esteemed winner of the very prestigious 2026 A' Design Award d'Argent in Disseny d'Arquitectura, Edificació i Estructures Competition Category.

ArgentArquitectura· 2026

Amami House Casa

by Kazunori Sakai

Client: Sakai Architects

A' Design Award d'Argent Winner in Arquitectura Category

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Verified Award Winner
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The Design

About Amami House Casa

Amami House és una residència autosuficient a l'illa d'Amami, al Japó, projectada per a una família de quatre membres. L'illa té un clima càlid i humit amb nivells baixos de radiació solar. La casa permet una vida confortable sense dependre de la xarxa elèctrica ni de l'aire condicionat. Estratègies passives com la ventilació natural, la il·luminació natural i l'aïllament redueixen la necessitat de sistemes mecànics. La forma tradicional de coberta a quatre aigües amb gablet es reinterpreta amb prestacions contemporànies. Un escalfador solar d'aigua, un sistema de compostatge i un hort domèstic completen un petit cicle d'autosuficiència.

The Recognition

About the A' Design Award d'Argent

Amami House Casa és un guanyador del guardó A' Design Award d'Argent, un reconeixement extraordinàriament prestigiós concedit a dissenys d'alta gamma, esplèndids i impressionants. Els guanyadors d'Argent són obres tremendament brillants i summament creatives que il·lustren la perícia, el talent i la perspicàcia excepcionals dels seus dissenyadors. Es preveu que Amami House Casa sigui una obra meravellosa i de gran lluïment, remarcablement professional i profundament innovadora. Aquest disseny guanyador del guardó A' Design Award d'Argent és un invent molt notable i admirat que beneficia i fa avançar els límits de l'art, la ciència, el disseny i la tecnologia. Amami House Casa és una creació molt envejada que evoca desitjos, introdueix sentiments positius i desperta sorpresa i admiració.

Behind the Design

Press Kit

Credits, team members and technical details provided by the designer.

Unique Properties: Located on Amami Island, an island with a hot and humid climate and among the lowest levels of solar radiation in Japan, this self-sufficient house investigates how a family of four can live comfortably without dependence on the power grid or air conditioning.

Rooted in the island’s unique climate and culture, the design reinterprets vernacular architecture through passive strategies, including natural ventilation, daylighting, and insulation, thereby minimizing reliance on mechanical systems.

The project presents a sustainable model of living in harmony with nature, nurturing resilience, and quietly redefining what it means to dwell in the modern world.
Dimensions & Packaging: A vacuum-tube solar water heater installed on the east-facing roof supplies domestic hot water, reaching 60 to 97 degrees Celsius in summer and around 30 degrees in winter. Only minimal backup from a gas heater is needed, reducing gas consumption to less than half of that in the family’s previous rental home. Groundwater use was initially considered, but high iron content led to the adoption of a public water supply for greater reliability. The sauna is heated with wood repurposed from local construction offcuts, creating a circular resource exchange with nearby builders. A composting system turns kitchen waste into fertilizer for the home garden, where vegetables grown on-site return to the dining table, forming a small yet tangible cycle of self-sufficiency.
Tags: Off-grid housing, Passive design, Self-sufficient living, Vernacular architecture, Japan, Sustainable architecture, Resilient design, Energy autonomy, Community living, Climate-responsive design
Production Technology: Amami is often called the “Island of Yui,” known for its deeply interwoven social ties. Traditional celebrations for children’s milestones often bring together more than 80 relatives and neighbors, reflecting a collective culture where child-rearing is shared across families and the wider community, and homes have historically functioned as both private and communal spaces. In recent years, however, such practices have diminished due to nuclear families, standardized housing, and the impact of the pandemic. This house responds by reintroducing openness and generosity into the domestic realm, creating spaces where people can naturally gather and share time together, reviving and sustaining the island’s cultural traditions.
Design Challenge: The hardest part was designing a truly self-sufficient house in one of Japan’s most demanding climates—hot, humid, and with limited solar radiation—while removing dependence on the power grid and air conditioning. Balancing comfort and resilience required continuous testing of passive strategies, energy autonomy, and spatial composition, with every decision responding precisely to local climate data. Equally challenging was integrating cultural elements such as the dispersed house form, the openness of yui community ties, and traditional roof expressions into a contemporary language sustaining both environmental and communal life.
Inspiration: Inspired by the vernacular landscapes of Amami, where corrugated metal roofs are commonly seen across local settlements, the design inherits the traditional hip-and-gable roof form and integrates contemporary performance features such as insulation, ventilation, and natural lighting. Through this synthesis, the project reinterprets and reconstructs the roof as a new architectural typology that connects local identity with modern functionality.
Project Duration: Design Period: February 2018 – December 2023
Construction Period: January 2024 – August 2024
Amami island, KAGOSHIMA, JAPAN.
Operation Flow: The project gently explores a sustainable way of living in harmony with the natural environment. Embracing the unique climate and culture of the southern islands, it quietly reexamines what it means to dwell in the modern age.
Team Members: KAZUNORI SAKAI（ARCHITECT)
MASAYUKI TAKATA (Structural Engineer)
TOMOHIRO URATA (Garden Designer)
KAZUHIKO HANAI (Lighting Designer)
KAZUNORI KAWAGUCHI (Main Contractor)
MAKOTO TANAKA (Carpenter)
MICHIHIKO MINESHIMA (Electrical Contractor)
YASUNORI SAKAE (Plumbing Contractor）
Image Credits: TOSHIHISA ISHII