By Andrea Hargraves 
A giant 3D printer applies layer after layer of a special cement mixture to build the walls of the first two model units of a hotel in Marfa, Texas. The company responsible is ICON, which completes the… The largest 3D printed district near Austin, Also in that country in North America.
The plan is to expand Cosmico– A hotel and camp with an area ranging from 85 m2 to 162 m2, to include 43 hotel units and 18 residential units.
Liz Lambert, owner of El Cosmico, is excited about what technology allows her to build.
“Most hotels are within four walls, and we were often building the same unit over and over again. I've never been able to build with so little constraint and this much flexibility using only curves, domes and parabolas. It's a crazy way to build.”
The 3D printed buildings designed by Bjarke Ingels Group incorporate domes, arches, vaults and parabolic or curved walls – architectural features that are usually too expensive to replicate on a large scale with traditional construction.
The 3.7-metre-high walls of the first two units currently under construction – a three-bedroom residential space and a one-bedroom hotel unit – were printed by ICON's Vulcan, a 15-metre-tall, 4.75-tonne printer that has printed the first residential neighborhood in 3D.
The “ink” for this 3D printer is a well-kept secret by the company: it's a special cement-based material called Lavacrete, a mixture designed to withstand the elements.
“The basic mix is a bit of a secret, so I won't give you the whole formula, so to speak. But we've narrowed it down to a list of materials that are available globally and everywhere, so we can do it in every single place,” said Jason Ballard, CEO and founder of ICON. All over the world and in an affordable way all over the world.”
Workers are constantly adjusting and mixing ingredients every 15 minutes depending on weather conditions.
“The magic happens in the mixtures that allow us to continue printing. This printer runs for about 36 hours straight and allows us to print overnight at 55°F (12°C). Today I think the max temperature will be 85°F (29°C) ) Therefore, the material behaves differently in different conditions of humidity, temperature and radiation levels. Therefore, we adjust the mixing components in the formulation slightly every 15 minutes, so that we can continue printing, literally, rain or shine.
A three-person team for such a project includes a print technician who monitors the printer and its preset path via software on a tablet.
The entire El Cosmico expansion project, to build 61 hotel and residential units, is expected to be completed in 2026.
In addition to this hotel development in West Texas, the ICON project was completed The largest 3D printed district near Austin and Working with NASA to develop 3D printing systems to build structures on the Moon.