Has House 3D Printing Finally Made It?

Outside of the additive manufacturing (AM) industry, one will often see the concept of additive construction referred to as “house 3D printing” or “3D printed construction.” Just see the results of the GoogleGOOG
keyword tool below. In part, this indicates the level of awareness that the general public has of this specific sector, as most mainstream news stories cover the increasing number of homes now being made with concrete 3D printing techniques. However, additive construction is now reaching a point where the sector is being valued for 3D printed housing and beyond.

Additive Construction Has Finally Made It

This is signaled by a number of developments, primarily the number of extremely large players that have entered the space. Many of the headlines we see today are being generated by some small startups, including ICON and COBOD, who build construction 3D printing systems. However, their customers are some of the largest on the planet.

For instance, COBOD—backed by the $1.8 billion PERI Group—is the supplier for GE, which recently built the world’s biggest additive construction facility to 3D print concrete bases for wind turbines. Holcim, the roughly $28-billion cement giant in hot water for making deals with ISIS in Syria, is another COBOD customer. It uses COBOD machines to 3D print homes and schools in Africa through its non-profit group 14trees.

ICON’s customers are arguably even bigger. In addition to collaborating with smaller housing developers, ICON’s primary partners are NASA and the U.S. Department of Defense. For the U.S. Army, ICON has 3D printed vehicle shelters and massive barracks.

Meanwhile, other conglomerates are getting into the sector, including CEMEX, the 5th largest building materials company in the world; Sika, a Swiss chemical giant with a current market capitalization of $38 billion; and Saint-Gobain, one of the world’s oldest and biggest construction materials multinationals with revenues of about $47 billion.

Where Did Additive Construction Come from?

Wohlers Associates, powered by ASTM International, is the 3D printing industry’s oldest and most-respected consulting firm. In April 2022, construction 3D printing expert Stephan Mansour joined Wohlers as an associate consultant, offering another sign that additive construction had made it. We know that construction 3D printing is more than just “house 3D printing,” but where did it come from? Mansour had some answers.

According to the specialist, additive construction got a significant boost from the Middle East, where the United Arab Emirates announced its 2030 Vision and Saudi Arabia unveiled its NEOM project. The former sought to make 25 percent of Dubai’s buildings 3D printed by 2030, while the latter injection $500 billion for planning and construction from the Public Investment Fund of Saudi Arabia and international investors.

“In response, general contractors initiated efforts to further investigate and realize additive for construction as a tool to deliver required objectives,” Mansour said. “Companies of note and key players in the gulf region included BAM Infra, BESIX, Freyssinet, Vinci, ACCIONA, and Consolidated Contractors Company. European advances and achievements in additive for construction over the past six years are a direct result of the previously mentioned companies. Based in Europe and working in collaboration with various material suppliers, technical institutions, and construction 3D printing startups, they look to realize additive for construction as a tool in the sector.”

This was further driven by a combination of the effects of the pandemic and the negative impact that traditional construction technologies have had on our ecosystem. According to Mansour, issues such as supply chain gaps, decreasing labor force, an increasing demand for construction, rising material costs, and client sustainability costs “are pushing the AEC sector to rethink the status quo and move towards additive for construction.”

What’s Next for Construction 3D Printing?

As this increased adoption occurs, there are two key areas that represent the next stage of development for additive construction, according to Mansour: enhancing the technology and making it more sustainable. In the first area, we’ll see such features as automated print monitoring through the use of sensors and artificial intelligence used to improve print quality. Additionally, the commissioning and decommissioning process for 3D printing equipment, especially for on-site printing, will be optimized.

As for sustainability, we already know that, if the cement industry were a country, it would be the third largest emitter of carbon dioxide in the world after China and the U.S. Mansour projects decreased reliance on this material in favor of metakaolin, adobe, lime stone, recycled construction waste, mine tailings, shales, and more. Similarly, new reinforcement materials will be explored, including hemp and hemp rebar, graphene, embedded fiber, and glass aggregates.

Of course, additive construction isn’t used solely for 3D printing concrete homes, nor will it be in the future. Mansour pointed out a number of applications beyond what is covered in most mainstream media, such as digital inventory to deal with cost overhead, lead times, and logistics; optimizing parts and 3D printing spares for aging construction equipment; more sustainable methods for creating facades, cladding, and structural connectors; and implementing a circular approach by using recycled materials like plastics and wood waste for 3D printing furniture and fixtures.

Additive Construction Standards

Moving forward, the biggest obstacle for the sector may not be technological in nature but associated with standards in additive construction.

“Nothing in construction happens without standards. There is no ‘redo’ in construction; a structure must be built to be safe and withstand the test of time and the elements. The construction sector is not averse to adopting new approaches and technologies but must be assured that the structures being ‘printed’ are safe and meet, or exceed, requirements. This is where standards play a crucial role,” Mansour said. “Standards enable mass adoption and acceptance, which fosters the creation of a healthy competitive market, which encourages further developments in materials and approaches, and enables competitive pricing.”

For this reason, Mansour took it upon himself to establish a committee to address the issue in March 2021. What came to become the ISO/TC 261/JG 80 committee drew up a draft standard, ISO/ASTM 52939, set to undergo a second review and commentary process before official publication by the end of 2022.

“This is timely, as it plays into several government led initiatives such as the recent European Commission proposal of March 30^th, 2022 where Additive for Construction is explicitly addressed and where the European Committee for Standardization (CEN and CENELEC) approved the adoption of ISO/ASTM 52939 as a CEN ISO/ASTM standard once published,” Mansour noted.

As we’ve seen with other 3D printing standards, this is only the beginning of what will be a long, laborious process that will be essential for pushing the sector forward. With this key work being performed, other efforts necessary to the progress of additive construction will be the continued education of industry professionals. In this regard, Wohlers Associates, powered by ASTM International, will advise and support the global construction sector by understanding the strengths and limitations of 3D printing as a tool. The organization offers strategic perspective on processes, materials, regulatory initiatives, and the development and adoption of industry standards.