New Story, a housing charity based in San Francisco, can build a community of 100 houses in El Salvador or Haiti in about eight months, with each dwelling costing about $6,000. But in a partnership with an Austin, Texas, technology company called ICON, New Story can look forward to building a new home in a single day at a cost of $4,000.

What’s putting this within reach is ICON’s 3-D printing equipment that created a 350-square-foot prototype house in Austin earlier this month. The building, described by Quartz as the first 3-D printed house to be code-compliant and approved for occupancy, was unveiled at the South by Southwest conference.

ICON’s Vulcan printer dispenses a concrete blend in strands roughly 1 inch thick, laying up the walls of the house layer by layer. The mix retains its shape as it’s placed and allows the printer to continue its programmed journey until the walls are complete. A crew must still install windows and doors, and frame the roof, but the entire process can take place in a day.

The houses may not look like high-end architectural award-winners, but they offer a way of providing safe, comfortable housing in regions of extreme poverty, and at a pace and price far superior to conventional construction.

Alexandria Lafci, a co-founder and chief operating officer at New Story, told Wired magazine that ICON’s technology is attractive because it can help alleviate a critical housing problem in much less time than conventional building programs could.

“There are over 100 million people living in slum conditions in what we call survival mode,” Lafci told the magazine. “How can we make a big dent in this instead of just solving it incrementally?”

Great potential ahead

As the article in Wired notes, architects and construction companies have been tinkering with 3-D printing technology to create buildings for a number of years. In 2013, a Chinese company printed 10 houses in one day, and later a six-story apartment building, and then an 11,000-square-foot mansion.

A San Francisco-based company called Apis Core printed an igloo-shaped house for about $10,000 in less than 24 hours at a site in Russia. The head of marketing for the company told Wired that the technology could be used to provide affordable housing for a large number of people in a short amount of time.

The prototype in Austin, however, is apparently the first printed house that could meet local code requirements and was ready for people to move in. ICON envisions upgrades to the process that would allow the robotic installation of windows after the walls have been printed, with drones spray-painting the walls. It may even be possible to develop techniques for printing roofs as well, although that’s not possible with materials and techniques currently available.

In addition to offering speed and lower construction costs, 3-D printing also makes it easy to create features that would be difficult with conventional construction. Printing complex shapes and curved walls, for example, would be no more difficult than building a plain box.

The printer ICON developed for the Austin house had to meet a number of conditions set by New Story, and overcome some technical hurdles in its inaugural run. Lafci told Wired that the plan now is to ship the device to El Salvador later in the year where it be put to work printing its first community of houses.

The Austin house is the only one that ICON’s Vulcan has printed to date, so how the printer performs on real job sites has yet to be seen. The process is still being refined, Quartz reports, but New Story hopes it will soon be possible to print an 800-square-foot house in just six hours.