A circular villa in harmony with Ishigaki Island’s nature

A spatial layout that balances functionality and views 

The main building is positioned within a crescent shaped zone on the southern edge of the site, while the surrounding areas are sculpted into a continuous, landscaped terrain. Although the architecture blends seamlessly into its natural context, the structure remains fully independent, allowing both environmental responsiveness and technical precision.

The gently sloping, bowl shape roof frames uninterrupted views of Ishigaki Island’s lush greenery and expansive sea. Appearing as though the hillside itself has been shaped into architecture, the design softens the boundary between built form and landscape, creating an immersive spatial experience that connects occupants directly with nature.

'Invisible comfort' through integrated design and services 

Arup developed a highly coordinated building services strategy that preserves the purity of the architectural expression while delivering exceptional comfort. The plant room is discreetly concealed within the building’s louvred elements, ensuring that all service equipment remains out of sight. Air-conditioning is delivered through refined ceiling slits, seamlessly integrated into the design to maintain a minimalist and uninterrupted interior.

To meet the demands of Ishigaki Island's subtropical climate, the environmental and services strategy required equally thoughtful solutions. A high‑efficiency heat‑pump system was introduced for pool heating, significantly reducing on gas consumption. A moisture‑resistant total heat exchanger enables continuous, energy-efficient ventilation by recovering heat from exhaust air, including bathrooms. Supplementary steam humidifiers provide rapid, hygienic control only when required.

An integrated control system, based on KNX technology, allows lighting, blinds, and air conditioning to be managed via tablet, enhancing user experience and operational efficiency. Given the remote island context, an emergency generator ensures resilience by maintaining essential systems during power outages. Together, these solutions deliver a refined balance of performance, reliability, and architectural integrity.

A structure that harmonises strength and lightness

The structural design combines durability with spatial openness. Reinforced concrete forms the primary structure, providing resilience not only against seismic forces but also against  the intense typhoon winds characteristic of the island’s coastal environment. To achieve expansive, unobstructed living spaces oriented toward the sea, post-tensioned concrete beams are employed, enabling large column-free areas that enhance the sense of openness.

Seismic stability is ensured through strategically positioned shear walls, carefully arranged to preserve key southern views. A U‑shaped structural configuration integrates with interior partitions and retaining walls, achieving both clarity of space and structural efficiency.

Where visual lightness is desired, slender steel columns are introduced as non‑load‑bearing elements. These refined vertical supports minimise visual impact while contributing to the overall architectural expression. The result is a carefully balanced composition in which the solidity of concrete and the delicacy of steel coexist in harmony.

_{Top image © NewColor inc}