Can you really print a 3D home for $10,000?

A 3D-print­ing busi­ness in the US says it can con­struct a home in half the time required to build a con­ven­tion­al equiv­a­lent – incur­ring only 10% of the labour cost and 10% of the waste. One of its rivals says it can print a house out for a shade over $10,000 (£7,100). It sounds rather too good to be true, doesn’t it?

One per­son who should know the answer is Hen­rik Lund-Nielsen. He’s the founder and gen­er­al man­ag­er of Copen­hagen-based firm Cobod, one of the world’s best-known house print­ers. His ver­dict? “The num­bers you see are usu­al­ly bull­shit.” 

First, the cost of the hous­es quot­ed in head­lines is mere­ly that of print­ing the con­crete walls, he says. None of the oth­er ele­ments of the build­ing – from win­dows to wiring – are priced in.

Sec­ond, there’s a lack of clar­i­ty about what’s actu­al­ly print­able. A pret­ty pic­ture of a fin­ished home sug­gests that the entire edi­fice came out of a noz­zle. In fact, only its walls are print­ed. The rest of the build­ing is made using more con­ven­tion­al meth­ods.

And third, speeds are often over­stat­ed. Lund-Nielsen’s research sug­gests that one much-pub­li­cised print­ed house that took “one day to build” had been under con­struc­tion for five months.

“The moti­va­tion is to gain the atten­tion of investors,” he says. “There is a 3D project in Chi­na that attract­ed a lot of pub­lic­i­ty. If the com­pa­ny behind it had told the truth, it would have got 10% of the cov­er­age.”

The mar­ket­ing tac­tics seem to be work­ing, though. “How many 3D print­ed build­ings in the world do you think there are?” Lund-Nielsen asks. “There are few­er than 50, but they are the prob­a­bly the most cel­e­brat­ed build­ings ever.”

Despite this, when you look through the hype there are still clear advan­tages to be gained by using 3D print­ing. Return­ing to the speed fac­tor, the print­er uses noz­zles on robot arms to extrude a thick con­crete – usu­al­ly a mix of cement, sand and addi­tives that accel­er­ate the set­ting process – in lay­ers. This method is gen­uine­ly fast. For instance, New York com­pa­ny SQ4D can make the walls of a 175m² house in 48 hours of print time spread over eight days. This oper­a­tion requires three peo­ple and the mate­ri­als cost $6,000 – num­bers that are hard to quib­ble with.

Then there’s design flex­i­bil­i­ty: the print­ers can pro­duce any shape. Pao­lo Guglielmi­ni is pres­i­dent of the man­u­fac­tur­ing intel­li­gence divi­sion at Hexa­gon, a devel­op­er of sim­u­la­tion soft­ware used by house print­ers such as Mighty Build­ings. He says that print­ing offers “unique flex­i­bil­i­ty, because there’s a more direct link between dig­i­tal design and pro­duc­tion. You print ideas.” 

Guglielmi­ni goes on to extol the ben­e­fits of sim­u­la­tion: “After the design, mate­r­i­al and process have been per­fect­ed at this stage, issues such as warpage, delam­i­na­tion and resid­ual stress will all have been elim­i­nat­ed vir­tu­al­ly when the home is print­ed, mean­ing there’s no need to waste time and mon­ey print­ing a four-tonne pro­to­type that’s warped and not in spec.”

The range of build­ing mate­ri­als that can be used is expand­ing too, offer­ing fur­ther flex­i­bil­i­ty. Light-gauge steel, for instance, can be print­ed on site or in a fac­to­ry. 

Jesus Jimenez is direc­tor at White Red Archi­tects, which has been involved in a 93-unit hous­ing project in Kent that’s using steel recy­cled from cars. “You build a skele­ton from the parts, like a mas­sive jig­saw,” he says, not­ing that the speed of the print­ing process slash­es labour costs. 

Every part can be print­ed bespoke – some­thing that’s hard to do using tra­di­tion­al fab­ri­ca­tion meth­ods. This makes it pos­si­ble to upgrade com­po­nents of exist­ing build­ings with print­ed light-gauge steel. Jimenez says: “The ten­ants in one build­ing to which we’re adding units don’t even need to move out.”

The more mate­r­i­al in a build that can be print­ed, the more cost-effi­cient that project is like­ly to be. Build­ings that don’t require much wiring, plumb­ing, tiling and oth­er labour-inten­sive tasks are par­tic­u­lar­ly suit­able. It’s why Cobod has been look­ing into pro­duc­ing wind­mills and ware­hous­es, says Lund-Nielsen, who believes that the labour costs asso­ci­at­ed with his sec­tor of the indus­try will inevitably rise.

“Try get­ting a young Eng­lish kid to work in con­struc­tion,” he says. “They don’t want to, but they might want a job where they con­trol a 3D robot with an iPad.”

Print­ing giant Ricoh thinks that the tech­nol­o­gy can add real val­ue to human­i­tar­i­an aid efforts. Richard Mini­fie, a senior engi­neer at the com­pa­ny, sees it as a dis­as­ter-relief solu­tion in remote loca­tions or a way to ease prob­lems caused by over­pop­u­la­tion in the devel­op­ing world, rather than a replace­ment for stan­dard hous­ing. 

“There is clear poten­tial for it in coun­tries lack­ing skilled labour or where it’s hard to organ­ise a work­place,” he says. “The first print­ed school in Mada­gas­car is set to open its doors this year, for instance.”

In the future, robots will be able to per­form tasks such as plas­ter­ing and run­ning cables. We may even see androids with super­hu­man strength work­ing on site. Boston Dynam­ics has already built Atlas, a dex­trous four-limbed robot with the abil­i­ty to break through con­crete pan­els.

So 3D house print­ing is here and, while the PR cam­paign sur­round­ing it should be tak­en with more than a pinch of salt, it offers sig­nif­i­cant effi­cien­cy sav­ings. For instance, Cal­i­for­nia-based Mighty Build­ings is offer­ing to install a ful­ly fur­nished one-bed house for $221,750 (£157,250). No hype – it’s ready to order today.

Even Lund-Nielsen – who esti­mates that “between 95% and 98% of the claims pub­lished by the indus­try are mis­lead­ing” – believes that the tech­nol­o­gy is set to change the world. Com­ing from the arch-scep­tic, that’s quite some­thing.