Casa Tertulia is a single-family residence located in San Mateo de Alajuela, Costa Rica, on a steeply sloping site with a dominant landscape condition. Its primary operation consists of providing housing through a strategy of minimal intrusion: rather than resting heavily on the ground, the house is elevated on stilts to reduce earthworks, allow ecological continuity beneath the structure, avoid interrupting natural runoff, and prevent flooding and humidity problems; making a complex site habitable without sacrificing accessibility or comfort for its elderly owners.
The project's syntactic organization is based on an "L"-shaped configuration that articulates two domains: the social and the private. This geometry does not respond solely to a functional distribution but also to a careful reading of the site. The house is set back behind an existing tree, preserving it as the environmental and perceptual center of the project. From this decision, vegetation becomes more than a scenic backdrop and instead serves as a spatial structure that filters views, shapes the arrival sequence, provides shade, accompanies movement through the site, and establishes a relationship of co-presence between human habitation and the ecosystem.
The perimeter corridor, also arranged in an "L" shape, is the project's primary architectural device. It functions simultaneously as circulation, living space, climatic threshold, and social space. Its generous and continuous character recalls Costa Rican vernacular traditions, where the corridor serves as a transitional space between interior and exterior, while also functioning as a domestic setting for gathering, rest, and contemplation. This reference is not adopted as a formal nostalgia but as environmental intelligence, as the corridor protects against solar radiation and rain, promotes cross ventilation, and expands the possibilities for everyday use.
The materiality reinforces this contextual reading. Wood, steel, and lightweight enclosures are employed with constructive rationality, avoiding an unnecessarily monumental image. The elevated structure, generous roof overhangs, permeable tapícheles, movable panels, and surfaces open to the landscape create a contemporary tropical architecture attentive to climate and to the precise use of resources. The house acknowledges that, in Costa Rica, housing cannot be understood separately from topography, humidity, shade, biodiversity, and the cultural ways of inhabiting outdoor space.
Casa Tertulia establishes a carefully calibrated coexistence with the site. Its relevance lies in demonstrating that housing can respond to concrete needs—accessibility, comfort, privacy, and domestic life—without turning the site into a passive support. The project transforms the fragility of the ecosystem into a design criterion and proposes an open, lightweight, and deeply site-specific domesticity.
Beyond its spatial organization, Casa Tertulia approaches sustainability through passive architectural strategies that work with the tropical climate rather than against it. Natural cross ventilation, permeable façades, operable timber screens, generous roof overhangs, and shaded transitional spaces reduce heat gain and improve thermal comfort while minimizing the need for mechanical cooling.
Its lightweight construction further lowers material consumption and embodied carbon, demonstrating how environmental performance can emerge from structural efficiency rather than technological complexity. Elevating the house above the steep terrain minimizes intervention on the site, preserves natural drainage, and protects the existing ecosystem. By allowing vegetation and wildlife to move beneath the building, the project maintains a continuous biological corridor that reinforces local biodiversity while reducing its ecological footprint.
Rather than treating sustainability as an added feature, Casa Tertulia draws from vernacular intelligence, where climate, landscape, and material economy shape the architecture itself. The project demonstrates that long-term environmental performance begins with careful design decisions that preserve more than they transform.
