Harvard

3D-Printed Buildings: Concrete Advances

Published on 25 April 2021

When many think of 3D printing, they probably imagine a desktop printer about the size of a toaster oven layering thin strands of plastic or resin to build small, unique shapes. They probably don't envision a massive machine, almost 12 feet tall and 33 feet wide, spitting out concrete to form thick, sturdy walls. However, this type of 3D printer very much exists, and it plays a central role in an emerging new market: 3D-printed buildings. As this technology expands, proponents anticipate it could solve the housing crises worldwide, providing sustainable, affordable homes to hundreds of millions over time. In response, however, critics argue that this idealism and excitement mask the technology's true nature— a passing, unrealistic fad.

3D printing, or additive manufacturing, is not a new technology. First developed in the 1980s, 3D printing involves layering thin bands of material according to a digital blueprint to construct a three-dimensional shape (1). Its wide applications include mechanical parts, instruments, food, and, more recently, housing. While there were many early endeavors into 3D printing structures, the first major advancements appeared in the early 2010s through several global projects. In 2014, for example, Amsterdam architects unveiled a 3D-printed canal house, and, the same year, Chinese company WinSun 3D printed 10 houses in a day for under $5,000 each (2)(3). As the technology expanded, so did the projects. In Dubai, WinSun collaborated with Dubai officials to print a functional office building in 2016 (4). By 2019, the city completed the largest 3D structure in the world (6,900 square feet) and declared that 25% of all buildings will be 3D printed by 2030 (5). In 2020, the German firm Peri announced construction of the country's first 3-D printed three-story apartment building (6). That same year, American firm ICON completed construction on a 3D-printed community for homeless individuals in Austin, Texas, one year after it announced construction of a 3D-printed neighborhood for families living in poverty in Tabasco, Mexico, in collaboration with nonprofits New Story and Echale which address homelessness globally and within Mexico, respectively (7)(8)(9). Most recently, this technology branched into the commercial sector as SQ4D listed the United States' first purchasable 3D-printed home in Riverhead, New York, in February, 2021, with several other firms announcing similar projects (10). In sum, 3D printing construction has expanded rapidly over the last eight years, and it has found promising footholds around the world in public, private, and nonprofit sectors far beyond those listed here.

"3D-printed construction" is more than just a buzzword— it offers important advantages over traditional building techniques, including speed, cost, sustainability, and safety. According to ICON's website, for example, each house requires only 24 total hours of printing time and between 3-4 on-site workers (11). This increased timeline and decreased labor can reduce labor costs by 50-80% and improve construction efficiency, features which could position 3D-printed structures as an affordable, widespread housing platform within the global housing crisis (12). Additionally, the technology increases building sustainability. 3D printing requires only the materials needed to construct the structure (as opposed to supporting materials) and does not generate scraps. Therefore, the process reduces building waste by up to 30% and requires less energy overall than traditional construction (13). 3D printing also can increase construction site safety, and its blueprint-based technology offers new opportunities for customized construction and individualized design (14). Finally, houses can be printed to specifically withstand natural disasters, leading to more durable homes and quicker roads to post-disaster regional recovery (15). 3D printing lowers costs, workplace hazards, and waste, all while increasing efficiency, customization, sustainability, and durability.

However, many remain doubtful of 3D printing construction, citing factors such as high printer costs, limited materials, governmental regulation, and market disruption. First and foremost, while each house may be cheap, the printer and software itself remain at a very high price point ($500,000-$2,000,000 per printer) which may be inaccessible to less-wealthy firms, especially in nations with lower labor wages (16)(17). Additionally, 3D printers can only build with materials that work with the machine, most commonly concrete. Therefore, any structures involving wood, glass, or plumbing must be added manually after printing, a process which decreases overall efficiency (18). Governmental regulation also often does not exist surrounding these structures, so such projects may require more bureaucratic logistics that undermine their proclaimed rapid timeline (19). Finally, critics worry that increased automation will displace workers in the construction and raw materials sectors. Globally, 100 million people are employed by the construction industry, which comprises 6% of global GDP (20). As 3D printing drastically reduces the labor and materials needed for construction, this technology, if adopted, could potentially displace many workers in construction, lumber, drywall, insulation, and other materials (21). Because the technology is so new, it remains to be seen if these structures can be sustained long term, or if they are simply a novel invention whose risks outweigh its benefits.

With their low costs and quick timelines, 3D-printed buildings are a promising development in the affordable housing and construction space. However, it remains too early to determine if they can feasibly be implemented on a larger scale, especially in lower-income communities that might need them the most. As the technology progresses, it will likely enable increased customization in high-income homes or public buildings. However, feasible implementation for low income individuals will require a widespread investment to improve the technology and make printers more affordable, accessible, and transportable. Nonetheless, the benefits of 3D printing structures remain too promising to ignore, and it is very possible that in the coming years this technology will revolutionize the construction and housing markets.

Sources

3D-Printed Buildings: Concrete Advances

Decarbonization of Real Estate with Machine Learning

Advancing the Armenian Economy: Policy and Action

Examining the U.S. Response to Covid 19: An Externalities-Based Approach

Why Teenage Mental Health Is Spiraling