DUST uses "lava-crete" to create monolithic desert house

DUST uses "lava-crete" to create monolithic desert house in Arizona

Arizona studio DUST has created a desert home south of Tucson using volcanic residue to form rammed-earth walls (+ slideshow).

The house, named Casa Caldera, sits at a high altitude in the Canelo Hills of Southern Arizona's San Rafael Valley.

Casa Caldera by DUST

It is made up of two solid volumes symmetrically organised around a central void. One contains the living spaces and kitchen, and the other contains two bedrooms and a bathroom.

In designing the house, the architects borrowed cues from vernacular desert architecture. The central space that separates the two volumes, referred to as a Zaguan, is typical of local architectural traditions.

Casa Caldera by DUST

"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," said DUST.

The only access to the house is through this sheltered courtyard space, which can be completely opened or closed by two massive steel doors at each end.

Casa Caldera by DUST

The courtyard frames views into the valley beyond, and in fair weather is used as the house's main dining area. A small secondary porch on the southwestern side of the house provides sunset views over the desert.

The house's two bedrooms are grouped together on one side of the courtyard, opposite the kitchen and living area.

Casa Caldera by DUST

The local climate allows for the house to have an open configuration. It only requires heating on a few days per year, which is provided by a wood-burning fireplace in the living room.

The site is a mere 15 miles (25 kilometres) from the Mexican border.

Casa Caldera by DUST

"Proximity to the border and immigrant related foot traffic led the owner to request an impenetrable structure," said the architects. To solidify the house, the 18-inch-thick (45 centimetres) walls were made of a material known as "lava-crete".

Casa Caldera by DUST

The material – a compound developed by American architect Paul Schwam – is comprised of a mixture of red pulverized lava rock, cement and water. It forms a semi-fluid material similar to concrete, which is rammed into formwork before it sets hard.

Besides providing security for the users, the depth of the walls acts as thermal mass, insulation, and principal structure all at once.

Casa Caldera by DUST

Additionally, the construction technique is a nod to traditional compacted earth walls found in desert homes throughout the southern United States and Mexico.

"From native agricultural cultures, to nomadic hunter-gatherers, to conquistadors and missionaries, to pioneers, miners, cattle, and cowboys, to militia, migrants, and narcotraficantes, this region is the landscape and folklore of the quintessential Wild West," said DUST, which also used rammed earth to create another house in the local area.

Casa Caldera by DUST

Rammed earth construction is a popular material for a wide range of building types. It has recently been used for a spiritual refuge by Aidlin Darling Design at California's Stanford University, as well as a villa for the staff of an animal breeding facility in Mexico's Maderas del Carmen natural park.

Photography is by Jeff Goldberg.