Can You 3D Print Your Dream Home?

If you love LEGOs, you might have imagined building a real house from them. And with the surging popularity of 3D printers, such a dream seems well within reach. Nick Johnson, a spokesman for real estate blog Movoto, decided to find out what it would take to build a 3D-printed house.

"Given that we're due to get our own 3D printer here in the Movoto office soon, I pretty much couldn't be more excited by the possibilities the technology introduces," Johnson wrote in a company blog post. "So, with that, I thought I'd look into exactly how realistic it would be to print the components needed to build a house using one of these devices."

As it turns out, if you were to use today's 3D printing technology, you would be long dead by the time your pieces were printed. In fact, it would take 220 years, four months and 11 days for a single machine to print the 27,735 bricks required to construct a 2,500-square-foot (232 square meters), two-story house. And if you think the endeavor sounds time-costly, you should read the price tag: $332,820 in plastic alone.

Johnson based his calculations on a MakerBot Replicator 2 printer and jumbo-size bricks measuring 8 in by 3.5 in by 2.75 in (20.3 cm by 8.9 cm by 7 cm). It would take nearly three days to print a single brick, and each brick would cost about $12 in ABS material. (ABS plastic filament is a must for this project, as the alternative — PLA — would begin to melt under the heat of the sun.) You can try Johnson's calculator for yourself:

But industrial 3D printing experts tell a different story.

Behrokh Khoshnevis, a professor at the University of Southern California who heads the Manufacturing Engineering Graduate Program, stunned a TED Talk audience earlier this year by showing it's possible to 3D print a 2,500-square-foot house in about 20 hours. Khoshnevis called the process "Contour Crafting," which would use a gigantic 3D printer erected over the footprint of where a building will stand. The 3D printer extrudes a concrete mixture, building a house layer by layer, the same way a desktop 3D printer makes a plastic figurine.

Khoshnevis said it's the cheapest form of construction — less expensive than prefabricated housing and infinitely customizable. "Every building can be very different just by changing the design," he said. "You could execute really exotic architectural features without incurring additional costs."

Once the basic structure was completed, finish work, tiling and even painting could also be done automatically with the kind of printers used for rendering billboards, he said.

Khoshnevis is currently working with NASA to design structures suitable for living on the moon. But long before Moon colonization becomes a reality, you may be able to print your own custom home here on Earth — imagine leasing a Contour Crafting machine at your local Home Depot.