DUST custom builds an off-grid arizona dwelling from volcanic rock
all images by cade hayes




in arizona’s san rafael valley, architectural alliance DUST has completed a dwelling designed in direct response to the region’s distinct history and context. located 15 miles north of the border between the united states and mexico, ‘casa caldera’ occupies a site formed by volcanic activity that resulted in a mineral and resource-rich land. ‘from native agricultural cultures, to nomadic hunter-gatherers, to conquistadors and missionaries, to pioneers, miners, cattle, and cowboys, to militia, migrants, and narcotraficantes., the san rafael valley in southern arizona is the quintessential landscape and folklore of the wild west’, says the design team.

DUST casa caldera
the dwelling is located in arizona’s san rafael valley




informed by climatic conditions, the small rectangular shelter is made from scoria — a basaltic lava that blends harmoniously with the landscape. walls are made from a porous, lightweight red volcanic aggregate, which is mixed to form a self-supporting semi-fluid and forced into formwork — similar to the process used for rammed earth. the clients requested both outdoor living and sleeping zones, a requirement that led to the rediscovery of a local house planning typology organized around a ‘zaguan’ — a type of hallway.

DUST casa caldera
the design is a direct response to the region’s distinct history and context




the home’s area of 880 square feet is broken into three rectangular zones, with living accommodation and sleeping quarters flanking the central zaguan. large folding metal doors on either end of the zaguan connect the covered living space to the surrounding landscape, ensuring natural light. these partitions also harness passive cooling breezes when open, and offer security when closed. consequently, this flexible volume can be used for lounging, dining, and sleeping. 

DUST casa caldera
the structure is found 15 miles north of the border between the united states and mexico




the zaguan as a space offers the rare experience where one can slow down or stop altogether, and simply take in the natural environment in a single focused view and physically witness time passing,’ explains DUST. ‘the only sources of heat are a wood burning stove and fireplace.’ cooling is achieved through the thermal offset of 18 inch-thick scoria walls and the natural flow of air that moves through the building as a result of positive and negative pressures on either side. solar orientation was carefully considered in the placement of external operable windows, which were kept small to minimize direct solar heat gain during summer months.

DUST casa caldera
the small rectangular shelter is made from scoria — a basaltic lava




‘casa caldera’ is almost entirely custom built, with its walls, windows, hardware, leather pulls, wood siding, millwork, casework and framing all fabricated and installed by DUST. an existing well provides water for the off-grid dwelling, and a small solar electrical system sits away from the house to provide basic electrical power use. minimal low voltage LED lighting is used, while cooking, water heating and refrigeration are all powered by propane gas.

DUST casa caldera
walls are made from a porous, lightweight red volcanic aggregate



video courtesy of jay bird films

DUST casa caldera
living accommodation and sleeping quarters flank the central ‘zaguan’

DUST casa caldera
solar orientation was carefully considered in the placement of external operable windows

DUST casa caldera
the only sources of heat are a wood burning stove and fireplace

DUST casa caldera
two bedrooms are provided

DUST casa caldera
large folding metal doors are placed at both ends of the zaguan

DUST casa caldera
the doors connect the covered living space to the surrounding landscape

DUST casa caldera
‘casa caldera’ is almost entirely custom built, and completely off-grid



video courtesy of ford photography



project info:


name: casa caldera
location: southeast arizona, san rafael valley, USA
completed: december 2015
interior area: 520 sqf / 48 sqm
footprint (including exterior terrace): 1,060 sqf / 98 sqm


client/owner: peter toot
architects: DUST
cade hayes, principal of DUST, project architect, registered architect
jesus robles, principal of DUST, project manager, design


general contractor: DUST
jesus robles, project manager
cade hayes, project manager
jay ritchey, carpentry
agustin valdez, concrete and masonry

  • Elegant – simple – love the materials.

    “The only issue” ..How could you sleep while squads of drug cartel mules marched thru the area .. or get windows thick enough to keep out intruders. Great effort, I hope the best for the building and its occupants.


    jimCan says:
  • …looks durable…where is the toilet? An outhouse or compostible? What about water? A well or tank for collecting rainwater?

    kfranger says:

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