Thanks to new extra-large 3D printers, it's now possible to print a house with a machine that extrudes a material - usually concrete/cement or a polymer, but more lately even earth - in an entirely additive process so there is exponentially less waste in construction.
Mighty Buildings can print a home in just 24 hours in their Oakland, CA factory using a thermoset polymer composite that is cured with a UV light (on the printer head). The process is fast enough for the material to support its own weight allowing for organic shapes but slow enough that there is cohesion between layers.
The company stayed in stealth mode while working through the regulatory challenges of such a novel technology. "The reality is the building codes are written in blood," explains Mighty Building's co-founder Sam Ruben, "and we want to make sure that we're actually getting ahead of that because we don't want 3D printing to get in the codes only when something goes wrong. So that's why we've moved iteratively to make it as easy as possible for building officials to say yes and allow us to begin delivering units while we continue to demonstrate and build out our portfolio."