Casa Caldera

Casa Caldera rests in a vast and remote desert landscape, in the space between trees. Their branches cast shadows over the rough texture of the poured lava-crete structure, and also shield the residence upon approach. This balance – between an atmospheric connection to the environment and a concrete sense of security in the midst of a vast wilderness – is established at the core of the project.

The client wanted an off-grid house that could celebrate its place in the remote landscape of Southern Arizona’s San Rafael Valley. A part of the rich biodiversity of the Madrean Archipelago, the “sky island” ranges serve as beacons for inhabitants of this seemingly endless desert landscape. They link Arizona to Mexico, and are essential to the story of life in this region: a refuge and resource base for migrating tribes, birds, and predators moving through the vast openness. Siting is balanced between the prospect of the open range and the distant mountains to the west – and is just 15 miles north of U.S. / Mexico Border. Due to this proximity to the border and immigration-related foot traffic, the owner requested an impenetrable structure.

Casa Caldera seems to rise simply from its earth, the walls – composed of a mixture of pulverized lightweight red scoria and cement – the same color as the dirt beneath. In one stroke, these walls form the structure; give it its rough, earthen finish; and provide insulation. The residence – compact at just under 1,000 square feet – takes cues from a vernacular “zaguan” housing typology. The plan is straightforward: two bedrooms sit opposite the living space, which includes kitchen, dining, and living room. The zaguan, or wide central hallway, runs between them. Large bi-fold doors, marked by steel panels that echo the formwork of the walls, offer an immediate sense of protected permeability: open, they frame the view and welcome in natural light and ventilation. Closed, they provide an impenetrable security.

The interior spaces are simple and light, minimal in design but with a soft material exuberance that saturates its atmosphere. The zaguan is wrapped in the gentle warmth of Sassafrass wood. Curated apertures cool the home and offer a tight frame for the expansive view, also shifting subtly the quality of light that drifts into the space and lands dappled against its richly tactile surfaces. The home is an insular, meditative, and deeply intimate experience, a careful negotiation of what is invited to enter the space.

The remote project is entirely self-sustaining: cooling is provided by a carefully balanced natural cross ventilation through the zaguan and strategically placed window openings, while wood fuel sourced on-property provides heating. Water comes from a well, and solar power is used for the minimal electrical and appliance needs. Casa Caldera sits lightly on the ground of its vast desert landscape, offering a mode of living that is as condensed as it is, fundamentally, connective.