Perched on the undulating coastal hills of Algarrobo, just ninety minutes west of Santiago, a new residence stands as a testament to the “expressive potential” of rational design. Casa SI, the latest work by the Santiago-based studio Iragüen Viñuela Arquitecto, is a 13-by-13-metre square dwelling that harmonizes factory-level precision with the rugged beauty of the Pacific horizon. As the primary residence for a couple relocating from northern Chile, the project represents a sophisticated experiment in prefabricated timber construction. By treating the building’s structural components as a “giant puzzle” manufactured off-site, the architects have managed to minimize construction errors while maximizing the home’s dialogue with its lush, southern ravine and western sea views. In an era of increasing housing demand, Casa SI offers a compelling blueprint for how modular systems can deliver warmth, character, and architectural quality.
A Mathematical Order in the Wilds
The defining characteristic of Casa SI is its unwavering commitment to a modular grid. Iragüen Viñuela established a strict one-by-one-metre grid that governs every aspect of the home’s layout, from the placement of structural pillars to the dimensions of the perimeter doors and windows. Secondary beams are spaced precisely at 50-centimetre intervals, creating a rhythmic, orderly framework that allowed for seamless integration with the prefabrication methods provided by Timber Ingeniería. This mathematical rigor was not chosen for the sake of austerity, but rather to ensure an “easy-to-build” structure that could be assembled quickly on a challenging sloped site.
By utilizing this grid, the architects were able to achieve a level of structural transparency where the “how” of the building is visible to the inhabitant. The frame is composed of glued-laminated (glulam) radiata pine elements, while the interior partitions utilize pressure-treated timber for durability. This approach significantly reduced the need for complex on-site adjustments, allowing the main dwelling to be erected with a level of efficiency that traditional construction rarely achieves. For Iragüen Viñuela, the grid serves as the foundational “language” of the house, providing a sense of stability and calm amidst the organic unpredictability of the coastal terrain.
Designing for the “Own Atmosphere”
Despite its rationalized construction, Casa SI is designed to feel profoundly intimate. The architects sought to create a home with its “own atmosphere”—a sanctuary that feels both light and grounded. To achieve this, the floor plan is intelligently zoned: the four corners of the square plan house the more private, enclosed functions such as bedrooms and service areas. This leaves the central portion of the house as a vast, open-plan space that integrates the kitchen, dining, and living rooms. This “heart” of the home is characterized by its visual depth, allowing residents to perceive all cardinal points of the property from a single vantage point.
The use of wood is central to the home’s sensory experience. The exterior is clad in painted pine siding, chosen for its ability to weather the salty coastal air, while the interior remains a celebration of the raw texture and warmth of radiata pine. Large stretches of glazing ensure that the boundaries between the interior and the landscape are porous. Interestingly, the architects chose to de-emphasize direct ocean views in certain areas to account for potential future developments in the neighborhood, instead focusing on the immediate beauty of the nearby ravine. This strategic orientation ensures that the home’s “atmosphere” remains protected and private, regardless of how the surrounding subdivision evolves.
Thermal Intelligence and Passive Strategy
Living on the Chilean coast requires a design that can handle shifting breezes and intense sunlight. Casa SI leverages its elevated position to facilitate natural cross-ventilation, capturing the cool Pacific winds to regulate the interior temperature without the need for intensive mechanical cooling. The “puzzle-like” assembly of the timber frame allowed for high-performance insulation to be integrated seamlessly into the wall panels, ensuring that the home remains thermally stable throughout the diverse Chilean seasons.
The elevated structure also serves a dual purpose: it minimizes the building’s footprint on the natural topography and provides a natural “plenum” for air circulation beneath the floorboards. This helps to mitigate moisture—a common challenge in coastal architecture—while also giving the house the appearance of “floating” above the hillside. This lightness is further emphasized by a network of wooden paths and outdoor staircases that interconnect the main house with a scenic overlook and a planned guest house. This “circuit” encourages residents to engage fully with their site, moving between the sheltered warmth of the timber interior and the expansive, salty air of the Algarrobo coast.
A Scalable Future for Timber Construction
Casa SI is more than just a single-family home; it is a successful case study for the burgeoning prefabricated timber industry in South America. Iragüen Viñuela’s collaboration with specialized manufacturers demonstrates that off-site fabrication can move beyond the “standardized box” to create bespoke, high-design architecture. The success of the project relied on “meticulous coordination” between the architects and the timber engineers, proving that when the design phase is rigorous, the construction phase can be revolutionary in its speed and simplicity.
As we look toward 2026 and beyond, projects like Casa SI suggest a shift in the residential market toward “engineered wood” products that offer predictability in performance and sustainability in sourcing. By using radiata pine—a renewable resource abundant in Chile—and minimizing on-site waste through prefabrication, Iragüen Viñuela has created a residence that is as responsible as it is beautiful. The “Puzzle House” stands as a reminder that in the hands of a skilled architect, a strict mathematical grid can become a gateway to total creative freedom and environmental harmony.
