Hanging from its mini gantry and free to move in any dimension except time, the nozzle on a 3D printer has pumped out plastic versions of everything – from prototype jet parts to prosthetic arms – and spawned something of a creative revolution. 
In just a few short years, it has proven itself as the inventor’s dream gadget.

While small 3D printers often take up less space than a microwave oven, it’s not that big a leap to imagine one 1,000 times that size.

Swap the plastic for fast-setting concrete and feed in a computer-designed drawing of a house, and a whole new world of possibilities opens up.

The idea of homes made with an industrial version of a 3D printer has become a major international talking point in the world of construction, with proponents claiming whole streets could be knocked up in a fraction of the time – and a fraction of the cost – of traditional methods. 3D-printed houses would be eco-friendly, cause less mess and noise during construction, and could transform the lives of millions.

It might all sound rather fantastical, but the race to bring the world its first 3D-printed house has apparently already been won. 
A Chinese company, WinSun, claims to have developed the technologies to build one and showed several rough but acceptable-looking finished models to the media last year. Californian professor Behrokh Khoshnevis, a leading light in the field of what he calls ‘Contour Crafting’ and a pioneer of printed-house technology, is unimpressed.

Khoshnevis says the Chinese don’t actually have a suitable machine for the job, and points out that all they have managed to make so far is a set of 3D-printed panels, which labourers then have to assemble into the finished product. Khoshnevis’ own plans in this field are infinitely more spectacular…

The global housing shortage is worse than you might think. According to the World Health Organisation, there are about a billion slum-dwellers around the globe trying to get by in makeshift homes. Often rife with disease and lacking basic facilities, life on the lowest rung of the housing ladder is dire and difficult to rise up from, not least because of the cost of buying a home made from bricks and mortar.

Khoshnevis’s own idea for a 3D-printed house is more in tune with traditional 3D printer use and he wants to construct a fully integrated house layer by layer from the ground up. He says that once his machine is up and running a three–bed family home could be built in 24 hours and for a fraction of the usual cost.

He doesn’t like to speculate on prices, but the Chinese 3D houses were built for a reported $5,000 (about Dh18,300) each. Based on those figures, a whole block of houses could be built for the price of a luxury Dubai apartment. And because the design of the homes would be dictated by the information the machine was being fed from a computer, no two houses need ever be the same.

“My idea is a fabrication process in which large parts can be made quickly in a layer-by-layer fashion,” explains Khoshnevis. “From the moment I first became aware of its possibilities I knew that it was going to go very far. The advantages include a superior surface finish and, of course, the speed of fabrication.”

In a matter of weeks, he says, a street of 20 detached, individually designed homes could be erected. Homeowners would be free to choose their own room configurations and architectural details, and second-generation 3D house printers would even be able to include electrical and plumbing cavities.

“I was always interested in construction and inventing things when I was a child growing up in Iran,” says Khoshnevis, a professor at the University Of Southern California in Los Angeles. “I am an unusual professor within the university as I have appointments in five different departments – industrial engineering, astronautics, mechanical and aerospace, civil engineering and biomedical engineering – because I have done work in every one of them. I’m basically just an inventor.”

Khoshnevis, 62, has been working on Contour Crafting for over of a decade, and the YouTube video of his talk at the popular ideas conference TED has notched up more than a million views. In it, he outlines his plans for an enormous gantry that would move forwards and backwards on tracks, just like a 3D printer.

A single artist’s impression of how it would work is all most people need to ‘get’ the idea, and the consensus seems to be, “Why not?” The answer, as with most things, is money. “It is difficult to advance because of the scale and the costs needed. I need a crew to run experiments, lots of space and finance, and in the university environment we don’t have that. But,” he says, with a confident tone, “we now hope to be building our first houses within a year.”

In the UAE, where construction has, of course, been high on the agenda for two decades, the idea of 3D-printed buildings is already catching on.

“I’ve had a lot of expressions of interest by a lot of well-known builders,” smiles Khoshnevis. “They all want it to be ready and say they will buy it when it is. Even skyscrapers would be possible. There are multiple applications.” For high-rise buildings, one way to do it would be to have his machine wrapped around the building and rising up with it as it grew, he says. Another would be to just keep moving the machine up. “You build the first floor and move the machine on to that to build the second floor and so on.”

But as he steadily moves his idea into the framework of a business, rather than a university project, Khoshnevis hopes to see a rapid acceleration of his work. It’s all relative though, and we shouldn’t expect to see his machines laying waste to the world’s building crews for some time yet.

“It’s not going to replace the construction industry,” he says. “It’s just going to start with a small sector of it. Construction is a field that encompasses not just houses but everything from roads to tunnels to bridges, and nothing’s going to happen overnight.”

He anticipates concern from workers’ unions in places like Los Angeles, but less so in places where unions are not so strong and labour costs are high, citing Japan as a good example. “There’s a lot of concern about people being put out of construction jobs, but in reality a lot of new jobs can be created as well,” he asserts. “Currently, women and the elderly do not have many opportunities to work in the construction industry, but with new technologies like this they can.”

As with all new businesses, there are problems to iron out. Khoshnevis is not, for example, allowed to build a house in the US right now because of legislative red tape. “If we built one and some homeless person moved in and there was an earthquake, we’d be liable,” he says. But excitement for his proposed machine – each one is expected to cost several hundred thousand US dollars – is contagious: almost everyone he speaks to has questions about how it would work, and how it could be tailored exactly to their needs. “There are always question marks,” he says, “but they’re not big ones. When the Wright Brothers invented the aeroplane, some people were perhaps saying, ‘Great, but what if you want to go to the restroom?’. No one could have conceived of passenger planes with hundreds of people in them. This is early-stage technology.”

If you’re mentally wishing Khoshnevis well but quietly dismissing his ideas as those of a sci-fi-loving dreamer, it’s worth noting that he already has multiple other products based around 3D printing in various stages of production; he owns multiple patents; and that there are already done deals in the construction industry that he can’t talk about. Oh, and that Nasa is among his biggest supporters.

“I have a project to build on Mars and the Moon,” he says. “What I’m proposing is a serious alternative for planetary construction.”

Artist renderings show large dome-shaped structures rising up on the surface of the moon, illustrating the idea that Contour Crafting is well suited not just to traditional, cube-like shapes but to more artistic forms, too.

His Moon project “allows for practically unlimited expansion of lunar settlements without requiring additional transport of major components from Earth.” Translation: send a printer and some concrete up into space, and stand back as it gets on with all the dirty work.

It would be rude to point out that the first visitors to Khoshnevis’s lunar base could well be the Chinese, who have publicly stated that putting man on the moon again is part of their space plan. Whatever happens, at least the Iranian inventor can find comfort in the fact that if the Chinese do take their own industrial-scale 3D printers with them, they’ll also need a small army of men to help put their moon-base together.

See www.contourcrafting.org