Grand Room House by IGArchitects: A Flexible Living Space Redefining Domestic Boundaries

Nestled on the edge of a residential development in Saitama, Grand Room House by IGArchitects reimagines the modern family home as a single, generous space where structure and flexibility coexist. Surrounded by a rural landscape and facing both a busy street and a quiet private lane, the site’s dual character inspired a design that bridges the openness of nature with the intimacy of domestic life.

A Dynamic Space for a Growing Family

Designed for a family of four, the home responds to the clients’ desire for a bright, expansive, and adaptable living environment that evolves with their lifestyle. At the heart of the project lies the “Grand Room”—a vast, five-meter-tall volume that occupies half the total area of the building. This multifunctional space integrates the living room, dining area, play zone, and even a garden, dissolving the boundaries between traditional domestic functions.

The Grand Room acts as a flexible core where daily activities unfold freely. Overhead zigzag beams—both structural and spatial elements—organize the space while guiding light, circulation, and visual rhythm. These beams not only provide structural stability but also serve as lighting rails, emphasizing the house’s open, modular character.

The Architecture of Continuity and Openness

The Grand Room forms a transitional zone between the public “town” and the cluster of private rooms, mediating between external and internal worlds. This fluid relationship allows the space to adapt seamlessly—whether for family gatherings, children’s play, or quiet reflection. The continuity of materials, particularly the warm expression of wood, enhances the tactile quality and invites natural light to animate the interior.

Instead of dividing the house into rooms defined by fixed purposes, IGArchitects designed a non-prescriptive space that supports multiple forms of living. This architectural openness allows the family to define their own rhythms—an evolving dialogue between structure and daily life.

Innovative Structural Strategy

To achieve the five-meter-high open volume, IGArchitects devised an inventive zigzag beam system that combines the roles of beam and brace using a single linear element. This configuration provides surface rigidity and wind resistance without relying on typical catwalks, dropped beams, or diagonal bracing. The result is a unified, expressive structure that enhances both spatial depth and visual perspective.

The zigzag framework creates a sculptural ceiling rhythm that reinforces the architectural identity of the Grand Room—at once robust and transparent, ordered yet fluid.

A Vision of Generosity and Adaptability

Grand Room House embodies the idea of flexible architecture—a space not constrained by conventional programs but open to reinterpretation over time. By centering the design around a single, expansive void rather than a series of closed rooms, IGArchitects redefines domestic comfort through spatial generosity, simplicity, and adaptability.

This residence stands as a thoughtful exploration of how architecture can support evolving family life, creating a home that is both structurally innovative and emotionally responsive.

All Photographs are works of Ooki Jingu