Future building: How 3D printing is paving new avenues in construction
3D printing in construction, also called 3DCP, makes use of robotics to deposit construction material in layers, creating walls, floors and roofs
Typically, a 2,000 square foot home takes about four months to construct. While it does not include the time taken to create the blueprints, or for power lines, windows and other finishing – it is still a long time, when compared to the newest building technology fast growing on the horizon: 3D printing.
The technology, in reality, has little to do with what the word printer typically evokes. 3D printing in construction, also called 3DCP, makes use of robotics to deposit construction material in layers, creating walls, floors and roofs. Some essential supports and reinforcements can be prefabricated by the machine and incorporated into a house as it is being built.
In other words, it is a far quicker way to create a structure – the build itself – than painstaking bricklaying and rebar reinforcement. Instead of four months in the above example, a 3D printed 2,000 square foot house can take as little as 7-10 days to erect.
Industry experts see 3D printing as the construction sector’s next big moment, and for a country like India, it holds a massive promise of affordable housing.
“If you build it, they will come. And if you 3D print it, they will come faster, cheaper and more sustainably,” Avi Reichental, CEO, chairman and co-founder of 3D printing company Nexa3D, said in 2018. Roughly five years later, in India and around the world, more people are beginning to understand what the prophecy meant.
In April 2021, Union finance minister Nirmala Sitharaman inaugurated India’s first 3D printed home in Chennai (it is within the IIT-Madras campus), made by a tech start-up called Tvasta. A 600-square foot, single-storey unit took three weeks to put together from printing to final construction, and the company said the cost was around ₹5.5 lakh, nearly a fifth of a typical 2-bedroom apartment in most parts of urban India.
“This technology can enable deep personalisation of construction. 3D printing can ensure that affordable, good quality housing is available to all Indians,” said Adithya VS, co-founder, Tvasta. The company claims the materials as well as techniques used result in about a third of waste generated, compared with conventional construction.
How it works
To build a 3D printed home is to begin at the basics of any construction plan: the blueprint. But instead of it being translated onto the ground by construction workers, a larger 3D printer takes a digital drawing to create a physical structure according to the scale finalised by the engineers.
The details available to the printer include specifics of dimensions, and details whether a particular wall is load bearing and the thickness required. The printing process involves placing different construction materials, in layers.
A 3D concrete printer includes a motion assembly, a dry-mix material feeding system, a continuous mixer, pumping unit, and an operating software that controls the motion assembly. A crucial component of construction printers is the nozzle.
“We have so far developed two gantry-based and two robotic systems-based 3D printers. These developments cost a third of European and American 3D concrete printing systems,” said Shashank Shekhar, CEO of MiCoB, an Indian 3D concrete printing solutions company.
The company has worked with Military Engineering Services (MES) to construct a 3D printed dwelling unit for the Indian Army, late last year.
While a 3D printer follows blueprints to build walls, pillars and roof, any additional elements such as windows, doors as well as electrical and plumbing systems, are put in place later.
“Concrete is one of the most used materials for 3D printed houses. It usually contains the dry components cement, sand, gravel, and aggregates,” according to Cobod, a company developing 3D printing solutions.
The composition is picked up by the printer and sprayed through a nozzle. “Those materials are later mixed with water to create a reaction that transforms the dry powder into a thick, liquid mass,” it added in an explainer of its technology.
But these are not easy. “A printing mix requires to possess certain properties such as faster preliminary setting; ability to be pumped out (pumpability), flowing nature (flowability) and ease of building one layer upon another without deformation (buildability),” explained Shekhar, adding that these are properties are not found in the mortar used in conventional construction.
According to latest numbers by Grand View Research, the global market for 3D printed homes was valued at around $13.84 billion in 2021 and is expected to register compounded growth rate of 20.8 percent through to the year 2030.
The promise in construction tracks with the global boom in 3D printing. Globally, 2.2 million 3D printers were shipped in 2021 and the number is expected to be as high as 21.5 million units by 2030, according to Grand View Research.
Within this, there will be a demarcation between specialised printers, and the more generic ones. 3D printers for construction are often intricately customised machines, unlike commercial 3D printers on sale on shopping platforms, including Amazon.in, where you can pick one up for ₹15,000 to create an object as large as a football.
India needs reliable housing solutions. In a 2020 report, the Indian Council for Research on International Economic Relations (ICRIER) estimated India’s urban housing shortage at 29 million units, up from 18.78 million in 2012.
According to government data, India’s construction sector was worth $126 billion in 2016, and is expected to grow as much as 7 times by the year 2028.
For a space that is nascent, it comes as no surprise there have been many “firsts”, in the past few years.
In 2014, a Chinese company Winsun made a 3D printed house, using four large 3D printers to spray concrete layer by layer, for constructing the walls. After this project in Shanghai, the company made 10 full-sized, single-storey houses in a day. They’re building what they describe as the world’s largest 3D printed complex, also in Shanghai, over an area of 50,000 square metres with seven buildings. It is expected to be completed in late 2023.
While many properties globally stake claim to be the first 3D house, there is belief that a family in Nantes in France, were the first in the world to move into a 3D-printed house, back in 2018. It is four-bedroom property, approximately 1,022 sq. ft. in size, and printed in 54 hours with insulator polyurethane and cement as the core materials.
The Guinness World Records title for the first commercial 3D printed building goes to the offices of the Dubai Future Academy – a 2,600 sq. ft. building that is 20 feet (ft) high, 120 ft long, and 40 ft wide.
But, 3D print construction is still in an early stage. A big question remains – what is the longevity prospect of these homes? There is no clear answer.
According to a study by researchers at the University of Nantes, 3D printed structures made with concrete have the potential to last for up to 100 years.
“In a nutshell, while we are using a novel methodology, learning and findings achieved over the last one century in the field of construction should not be overlooked and should be taken as a baseline for the further improvement,” said Shekhar.