All About 3D Printed Buildings

I’m obsessed with 3D printed buildings because it’s clearly the next big step in construction. There’s a long ways to go before it’s mainstream, but all the early signs are promising.

Modular Homes are like Hybrid Cars

There are plenty of companies out there focusing on modular housing, shifting construction into controlled warehouse conditions. But I see them as the hybrid cars of housing- it’s just a stepping stone. None of the modular home builders I’ve spoken to provide much of a cost or time savings versus traditional methods.

If the factories aren’t backed up, modular building can achieve schedule gains and improved safety. But those factors haven’t been revolutionary enough to make it an obvious option for developers. So it’s struggled to gain traction.

3D Printing on the other hand, has the potential for significant cost and schedule savings. Most prints I’ve seen require much less human labor and can be completed in a matter of days. And as the technology evolves, we could build more complex structures with less material.

A Brief History of 3D Printing

The concept of 3D printing, or additive manufacturing, surprisingly wasn’t all that far behind 2D inkjet printing. The first mentions were in a science fiction magazine in 1950. 2 decades later the ideas were published in an actual science journal.

3D Printing Methods

By the 1980’s things started moving with a few patents being filed for different 3D printing methods.

The first method was a Stereolithography Apparatus, or SLA. The apparatus shoots ultraviolet laser beams under a pool of liquid photosensitive polymer to selectively harden portions of it, one layer at a time. This is the method that looks like the T1000 rising out of the floor.

The second method is called Selective Laser Sintering. It’s an upside down version of SLA using powder instead of a liquid polymer. Lasers are aimed at a flat bed of powder, selectively hardening the areas that the laser hits. Then a platform lowers the object and the powder bed is refreshed for the next layer.

The third method is Fused deposition modeling, or FDM. Also known as Fused Filament Fabrication, it’s the technology that extrudes a spool of a thermoplastic filament through a printer head mounted on a gantry. It moves across an XY plane, extruding heated filament until an entire layer is done. Then the platform with the printed object shifts down on the Z plane to allow the next layer to be printed.

Then Nothing Much Happened

Companies formed around these patents, but with the exception of a 3D printed organ in 1999, a whole lot of nothing happened. (This is reminiscent of e-ink corporation deciding what applications are commercially viable).

By 2009, the fused deposition modeling, or FDM patent expired and with FDM printers dropping in price from $10,000 to $1,000 things really started to pick up.

3D Printing Shows Signs of Life

By 2011, students at Southampton University used SLA to 3D print a functional unmanned aircraft. Kor Ecologic 3D printed the body for a prototype car called the Urbee. And in 2012, Makerbot launched as a kickstarter project, and Stratasys bought them in 2013 for $400 million. In 2019, pretty much all the patents expired and companies have been popping up everywhere to advance the technology.

Seventy years after being published in a science fiction magazine as a pie in the sky idea, 3D printing is finally showing its true potential. There are countless applications of 3D printing on a small scale, but the benefits will be literally enormous when scaled up for construction.

And sure enough, over the last 7 years, there have been a handful of companies and researchers in academia pursuing large format 3D printing for buildings.

3D Printed Buildings Start Popping Up

WinSun

The first reported 3D printed buildings were completed by the world’s biggest real estate developer: China. A company called WinSun quietly announced in 2014 that they had 3D printed 10 houses in 24 hours, using a mix of cement and construction waste. But nobody really took them seriously because of China’s lax building regulations and the rough design quality. To gain some legitimacy, they collaborated with Gensler in 2015 to 3D print the outer shell of a fully functional office of the future in Dubai.

In 2016 they faced some literally stiff competition from HuaShang Tengda. This 2-story 4300 square foot house can withstand an 8.0 earthquake on the Richter scale. So Winsun answered back with a 3D printed 5-story apartment building.

Apis Cor

That same year, the San Francisco-based Russian company Apis Cor made waves by releasing a video showing a small 1-story house they printed in 24 hours. They built a huge version of the FDM method of 3D printing, using fast drying concrete mortar as a filament. Then they transported the robotic arm to the construction site and the house was printed in place. The roof and finishes were constructed using traditional methods after the print.

ApisCor one-upped themselves AND Winsun by printing much bigger building in Dubai. With an area of almost 7000 sf, they claimed the title of largest 3D printed building. Winsun one-upped them a year later by building the largest 3D printed structure of any kind, a 1,640-foot long wall in Suzhou river to prevent shoreline erosion.

More 3D Printed Houses Appear

By 2017 the concept started picking up steam. University of Nantes built Yhnova House in France by 3D printing a foam mold and casting the concrete. Someone actually lives in it now.

In 2018, an Italian 3D printing company called WASP printed a small home in Italy out of local naturally occurring materials. And Washington University in St Louis entered the fray in China with their Lotus House, using the 3D printed mold technique. Their mold, however, could be reused 100 times and significantly reduces carbon emissions and waste over traditional construction methods.

Icon Build

The biggest leap forward that year was actually from a Texas based company called Icon Build, founded by Jason Ballard, Alex Le Roux, and Evan Loomis. They didn’t try anything flashy or big. They just built a really small house using a really big gantry system for $4,000. And that took the title of first 3D printed home in America.

Icon Build differentiated with a real business model, whereas all the other homes to that point were just showcasing technology. They set out to pursue printing cheap homes for the homeless in 3rd world countries… and then shoot for the moon. No literally. They secured a $35m round of venture funding in 2020 and won a NASA contract to design construction systems for future moon missions.

AI Space Factory

Speaking of interplanetary developers, former KPF architects David Malott, David Riedel, and Michael Bentle founded NYC-based AI Space Factory around the same time. On the terrestrial side of their business, they approached the market from the luxury end, packing their 2-story house design with all sorts of technology and raising money for their first house on indiegogo.

On the extraterrestrial side, they also won a $500,000 NASA award for the 3D printed Mars Habitat initiative. Their 30-hour print used a biodegradable basalt composite that’s stronger than concrete, and it needed almost no human assistance.

In 2020, Long Island based company SQ4D printed the largest PERMITTED home in the US and put it up for sale. I visited this one in person.

What’s next for 3D Printed Buildings?

Each of these companies are always pursuing higher print resolutions, meaning thinner layers and smoother surfaces. They’re also exploring different print substrates for greater structural integrity and faster print times. Once they can pass certain size, resolution, cost, and structural thresholds, it will likely trigger a rapid adoption of the technology. Academia gives us the biggest hints of what’s coming.

DFAB house was an ETH Zurich project combining robotics, 3D printing, digital design, and home automation technologies. This three story building showcases an array of different materials and construction techniques, like curved concrete formed from 3D printed molds on one floor, and wood frames arranged by robots into complex geometries on another floor.

Looking further ahead, MIT Media Lab’s mediated matter division is lightyears ahead of commercially viable technology. PhD graduate Steven Keating did his 2016 thesis on a project where he and a few other masters students built a self-driving robotic crane with 6 degrees of articulation, which has way more range of motion to print crazy shapes than any of the companies mentioned before. Sadly, Keating passed away in 2019 after suffering from a massive brain tumor.

MIT Media Lab continues to show us hints of the future with lots of research into robotic swarms. This actually scales down 3D printing, but with the end goal of printing even larger scale structures. Miniature robots can act as tiny 3D printers by climbing or flying over to where they need to extrude some material.

I’m looking forward to working for our future robot overlords, but til then, stay curious noobs.