The world's first 3D-printed house

Zero waste, lower transport costs and recyclable materials – is 3D-printing the future of housebuilding? Dutch architects are putting the process to the test for the first time in Amsterdam

3D-printed house … The future of volume house-building, or a novelty technology for temporary pavilions? Photograph: Peter Dejong/ASSOCIATED PRESS

Treacle-black plastic oozes from a nozzle at the bottom of a small tower in Amsterdam, depositing layer upon layer of glistening black worms in an orderly grid. With a knot of pipes and wires rising up to a big hopper, it looks like a high-tech liquorice production line. But this could be the future of house-building, if Dus Architects have their way.
On this small canal-side plot in the north of the city, dotted with twisting plastic columns and strange zig-zag building blocks, the architects have begun making what they say will be the world's first 3D-printed house.
“The building industry is one of the most polluting and inefficient industries out there,” says Hedwig Heinsman of Dus. “With 3D-printing, there is zero waste, reduced transportation costs, and everything can be melted down and recycled. This could revolutionise how we make our cities.”
Working on site for three weeks, the architects have so far produced a 3m-high sample corner of their future house, printed as a single piece weighing 180kg. It is one of the building blocks that will be stacked up like Lego bricks over the next three years to form a 13-room complex, modelled on a traditional Dutch gabled canal house, but with hand-laid bricks replaced by a faceted plastic facade, scripted by computer software.

At the centre of the process is the KamerMaker, or Room Builder, a scaled-up version of an open-source home 3D-printer, developed with Dutch firm Ultimaker. It uses the same principle of extruding layers of molten plastic, only enlarged about 10 times, from printing desktop trinkets to chunks of buildings up to 2x2x3.5m high.
For a machine-made material, the samples have an intriguingly hand-made finish. In places, it looks like bunches of black spaghetti. There are lumps and bumps, knots and wiggles, seams where the print head appears to have paused or slipped, spurting out more black goo than expected.
“We're still perfecting the technology,” says Heinsman. The current material is a bio-plastic mix, usually used as an industrial adhesive, containing 75% plant oil and reinforced with microfibres. They have also produced tests with a translucent plastic and a wood fibre mix, like a liquid form of MDF that can later be sawn and sanded. “We will continue to test over the next three years, as the technology evolves,” she says. “With a second nozzle, you could print multiple materials simultaneously, with structure and insulation side by side.”

For now, these plastic blocks, which are printed with a honeycomb lattice within for reinforcement, are back-filled with lightweight concrete, for structural strength and insulation – which would make recycling the parts somewhat difficult.
“It's an experiment,” says Heinsman. “We called it the room maker, but it's also a conversation maker.” Over 2,000 people have already visited the site, from building contractors to coach-loads of architecture students, while even Barack Obama was shown the prototypes when he was in Amsterdam last week.
“This is only the beginning, but there could be endless possibilities, from printing functional solutions locally in slums and disaster areas, to high-end hotel rooms that are individually customised and printed in marble dust.”

Countour crafting … Researchers at the University of Southern California have been developing a technology that 'prints' quick-setting concrete from a computer controlled gantry. Photograph: Contour Crafting

While Dus may be the first architects to start printing a full-scale house, they join a number of others who have been experimenting with printing at an architectural scale over the last few years. Since 2008, researchers at the University of Southern California have been developing a technology, known as contour crafting, that uses a computer-controlled gantry to print structures in quick-setting concrete, which they say is potentially capable of printing high-rise buildings, with the printer climbing the structure as it grows. Another Dutch architect, Janjaap Ruijssenaars, is working on a project to print a house shaped like a looping Mobius strip with the Italian-made D-Shape printer, which uses sand mixed with a binding agent to create a form of synthetic sandstone. So far, only a small pavilion-sized structure has been printed. This looks to be where the technology will remain for the time being: temporary novelty structures for exhibitions and events.
“One of my fantasies is printing in biodegradable materials for festivals,” says Heinsman. “You could print an outrageous tent structure, then after a couple of years and few rain showers it disappears.”

Full story at the theguardian.com