Printing a home

The idiom “brick by brick” may become outdated and replaced by “layer by layer” in years to come. With several countries, companies, and entrepreneurs successfully experimenting with construction 3D printing, the housing industry appears poised for a sea change.

TVASTA Manufacturing Solutions, a start-up run by alumni of IIT Madras, recently unveiled India’s first 3D printed house — a single storey building with functional space of about 600 sq ft, comprising a bedroom, hall, and kitchen. It used the “concrete 3D printing” technique.

The house, on the campus of IIT Madras, was virtually inaugurated by Finance Minister Nirmala Sitharaman, who said India needed such solutions to achieve the prime minister’s goal of “Housing for All by 2022”. “Conventional houses require timing, material, logistics, transporting material, and so on. If this technology can produce houses at different locales at five days per house, it won’t be a big challenge to build 100 million houses by 2022,” she said.

TVASTA’S co-founder Adithya V S said: “This technology can enable deep personalisation of construction for the ultimate target segment — who is the individual. 3D printing can ensure that affordable, good quality housing is available to all Indians."

This technology can be used for military constructions, besides rehabilitation in disaster-hit areas and for sanitation purposes. Scientists are also working on a plan to use it for building the first houses on Mars, besides lunar stations. Dubai plans a quarter of its buildings to be 3D printed by 2030.

3D printing a house is considered to be easy and cost-effective in terms of materials and labour. For many people decent housing is still a luxury and, according to experts, a construction 3D printer can help solve this issue. But is it the panacea to all these issues? Currently, this is only an assumption; there’s a long distance to cover before objectively comparing it with the traditional method construction using bricks and mortar/mud, which have been in use since 9000 BC.

So, how does it work? Three techniques are currently being explored to accelerate processes and lower costs in architecture — D-shape, contour crafting, and concrete printing. D-shape uses a large 3-dimensional printer and binderjetting — a layer-by-layer printing process to bind sand with inorganic seawater and magnesium-based binder to create stonelike objects.

Contour crafting is based on emitting multiple layers of a cement-based paste against a trowel, allowing a smooth surface finish. It is being used in large-scale constructions. Concrete printing, which like contour crafting, is based on the extrusion of cement mortar in a layer-bylayer process, but without trowels.

These techniques have one key difference — whether the head mounting (the part that delivers material) is frame, robot or crane-mounted. Contour crafting has been developed to be a crane-mounted device for on-site applications. Both Dshape and concrete printing are gantrybased off-site processes.

With several clients nowadays demanding unique, non-uniform structures that are extremely difficult to be built by traditional methods, 3D printing becomes a likely solution, which may also help reduce costs (according to an estimate, it helps cut labour cost for a project by 80 per cent), building time, waste, and on-site safety concerns.

It’s noted that most 3D printed houses are conceptual. There is essentially no regulation or process for approving 3D printed structures for residential or commercial use — governments will first need to come up with standards to ensure their structural integrity (including requirements stipulated in a seismic zone), besides public safety. In some countries, such as Germany and the Netherlands, a few such buildings have been declared safe for living.

Also, innovation and disruptive technology bring new legal challenges. “In the context of construction defects claims, 3D printers will expose manufacturers and developers to liability and claims that would normally be attributed to human error,” wrote Aldo E Ibarra in Engineering News-record.

Moreover, any design-based alteration would be difficult once the process of printing starts and may incur a heavy cost depending on the stage of printing. “Since design has to be completed before printing, flexibility in design as expected by many clients will be curtailed,” said Soma Chandra, faculty, Dayananda Sagar College of Architecture in Bengaluru.

“Also, there will be a learning curve for architects, engineers, contractors, and other collaborators on such projects. For widespread application and to harvest the potential of this technology, skill levels have to be upgraded for the workforce,” she said. There will be challenges with mobilisation of the printer and repair while 3D printing houses in remote areas.

The construction industry in India, according to various estimates, employs around 50 million people. How the need for a smaller workforce because of 3D printing would impact their livelihood is a reason for concern.

3D printing may open up new, unforeseen solutions but will it be truly revolutionary? Without weeding out major concerns, automated construction may not be widespread for several years.