A startup called Icon says it can make a 650-square-foot house using 3-D printing in 12 to 24 hours.

A trial run: The first home constructed using Icon’s technology is being unveiled at SXSW in Austin, Texas, today. One of its founders, Jason Ballard, will be testing out the home by living in it.

The cost: Right now, a house built using the firm’s Vulcan 3-D printer costs $10,000. The company says it will be able to lower that to a mere $4,000.

But: These are big promises. People have been trying to make 3-D-printed houses for a while—we reported on one experiment back in 2012. But engineers keep running into roadblocks, like equipment failures or issues about how long walls should dry. Some obstacles are starting to be overcome, but plenty remain.

Next steps: The Verge says Icon plans to construct 100 homes in El Salvador in 2019. If it can actually do that on time and on budget, it will show that 3-D-printed homes aren’t just an experiment anymore. But that’s a big if.