The Netherlands needs thousands of new homes to accommodate its growing population and it might not build them all – some may end up being printed.
As part of a program exploring how the country can create the homes it needs, Elize Lutz and Harrie Dekkers have moved into a new 94-square-metre, two-bedroom home that resembles a boulder with windows.
The curving lines of its grey concrete walls look and feel natural, but they are actually at the cutting edge of housing construction technology in the Netherlands and around the world.
They were 3D printed at a nearby factory.
"It's special. It's a form that's unusual, and when I saw it for the first time, it reminds me of something you knew when you were young," Ms Lutz said.
She will rent the house with Mr Dekkers for six months for 800 euros ($1,245) per month.
Home took 120 hours to print
Fittingly, Ms Lutz and Mr Dekkers' new house is in Eindhoven, a city that markets itself as a centre of innovation.
The home is made up of 24 concrete units "printed" by a machine that squirts layer upon layer of concrete at a factory in the city before being trucked to a neighbourhood of other new homes.
There, the finishing touches — including a roof — were added.
The layers give a ribbed texture to its walls, inside and out.
The house complies with all Dutch construction codes, and the printing process took just 120 hours.
The home is the product of collaboration between city hall, Eindhoven's Technical University and construction companies called Project Milestone.
Printed homes use a third less concrete
In the future, as the Netherlands seeks ways to tackle a chronic housing shortage, such construction could become commonplace.
The country needs thousands of new homes this decade to accommodate its increasing population.
Theo Salet, a professor at Eindhoven's Technical University, has been working in 3D printing to find ways of making concrete construction more sustainable.
He figures houses can be 3D printed in the future using 30 per cent less material than traditional construction methods.
"Why? The answer is sustainability," he said.
"And the first way to do that is by cutting down the amount of concrete that we use."
He explained that 3D printing can deposit the material only where it is needed.
There are plans to build a total of five houses, and future homes will have more than one floor.
The process uses concrete the consistency of toothpaste, Mr Salet said.
That ensures it is strong enough to build with but also wet enough so the layers stick to one another. The printed elements are hollow and filled with insulation material.
The hope is that such homes, which are quicker to build than traditional houses, could become a factor in solving housing shortages in a nation with a population of 17.4 million people and rising.
In a report this month, the Netherlands Environmental Assessment Agency said that education and innovation can spur the construction industry in the long term.
But other measures are needed to tackle Dutch housing shortages, including reforming zoning.
Mr Salet believes 3D printing can help by digitising the design and production of houses.
"If you ask me, 'Will we build one million of the houses, as you see here?' The answer is no. But will we use this technology as part of other houses combined with wooden structures? Combined with other materials? Then my answer is yes," he said.
Mr Dekkers has already noticed great acoustics in the home, even when he's just playing music on his phone.
And when he's not listening to music, he enjoys the silence that the insulated walls provide.
India printing homes too
India's first 3D-printed home was unveiled in April.
The single-storey home, measuring about 56-square metres was made in the southern Indian city of Chennai.
These homes can be built in just five days and be customised, so the technology is seen as suitable for the government's affordable housing program, as well as for disaster resettlement.
Prime Minister Narendra Modi's government has pledged to create 20 million new urban housing units and 30 million rural homes by 2022 under the Housing for All scheme.
Large-scale 3D printing is gaining steam around the world, with some projects producing a home in just 24 hours of printing time.
ABC/Wires
