Going back to the days when it was called "rapid prototyping," 3D printing was supposed to be about saving money. 3D printed houses offered that promise too, but it hasn't shaken out yet, at least not in the 'States. Those 3D-printed houses in Texas are priced at $450,000.

In contrast, Japanese housing startup Serendix just built their first 3D printed house, and the price is ¥5.5 million (USD $37,824). Obviously they're small, given the Japanese market, at 50 square meters (538 square feet), but the idea is to provide elderly/childless couples "a house that can be bought for the price of a car," as the company writes. "Aiming to realize a life free from mortgages, we are working with more than 205 open consortium companies to solve housing issues in three aspects: Technology, housing, and price."

The design of their Barnacle House, as it's called, is by architect Emu Masuyama and engineer Hiroya Tanaka, of Keio University and Miyagi University, respectively. It's one-story and minimal, just enough for a couple:

Serendix built the first model this month. The Barnacle was 3D-printed in sections, rather than in a single go, and assembled on-site. The company says the construction process took just 44 hours and 30 minutes.

A concrete foundation was poured, with steel columns embedded in the slab. The wall sections have cavities inside that allow them to be slid over these columns. The wall sections are connected with reinforcing bars, then locked in place with ready-mixed concrete.

The roof is not 3D printed, but is instead made of CNC-cut wooden members that form a frame. The frame is clad in construction-grade plywood. (I was not able to learn, through the machine-translated press release, what the roof frame was then coated with.) The roof is then craned into place. Windows and doors are then fitted.

Serendix says the house is structurally strong, resistant to damage from fire and water, and offers good insulation. And you really can't beat that price, especially in Japan. "We would like to break the current cycle of 30-year mortgages with an average maturity date of 73 years, where 40% of Japanese people cannot own a home for the rest of their lives," the company writes.

Unsurprisingly, they've already racked up 3,000 reservations and inquiries.