Construction is one of the most ancient human activities, with the earliest techniques using bone, hide, stone, and wood tools dating back to as far as 9000 BC.

But the modern engineering, construction, and infrastructure (ECI) industry is also one of the fastest-changing industries globally – especially today, as it grapples with increased demand, snarled supply chains, and ever-increasing cost pressures.

The use of on-site mobile apps, construction management software suites, and even AI and machine learning applications for improving project productivity are just a few examples.

Another is the emerging use of 3D printing in construction and renovation projects.

While not yet an everyday tool, the technology has already been deployed at high-profile job sites such as the Parliamentary Precinct restoration in Ottawa, Canada, and municipal administrative buildings in Dubai, United Arab Emirates.

But what is it about 3D printing that’s so attractive to the construction industry? Let’s find out.

What is 3D printing and construction?

3D printing, also known as additive manufacturing, has been around since the 1980s but only became viable for commercial use in the early 2000s. While initially used primarily for prototyping and product design, 3D printing now has a variety of uses, including component manufacturing and aerospace engineering.

Construction 3D printers are developed specifically for the construction industry and are typically used to print a building’s frame and walls.

Indeed, printing an entire, fully-functional building – including plumbing, windows, wiring, HVAC, kitchen fixtures, and other elements – with a 3D printer all in one go is still the stuff of science fiction.

But printing various components for commercial and residential construction projects is now very much a real thing, albeit with significant capital costs: Construction-focused printers such as the Maxi Printer and COBOD BOD2 run between $300,000 and $550,000 apiece.

Either way, the market for 3D printing in construction is growing rapidly – so rapidly that it has even taken industry watchers by surprise in some cases. “3D printing [on a wide scale] is a lot closer than I thought,” University of Denver professor Eric Holt, a construction management expert, told Metropolis Magazine last year. “I used to believe it was at least five years out, but the ball has moved really quickly.”

Some 3D printing construction companies, such as Mighty Buildings, have taken things even further. Mighty Buildings uses a combination of 3D printing, high-tech composites, robotic finishing, pre-built bathroom pods, and 3D scanning to produce three-bedroom houses in two to three weeks.

The company’s CEO says that although Mighty Buildings eventually hopes to be able to 3D print entire buildings, the company currently uses a panelized technique involving off-site fabrication and reassembly.

How does 3D printing in construction work?

The process of fabricating walls, components, or virtually anything else with a construction 3D printer can vary, but generally involves the following steps:

1. A 3D digital model is created of the item (typically in computer-aided design (CAD) software)
2. Model data is then fed to the 3D printer, which reads the design
3. Successive layers of material (including metals, liquids, powders, or other composites) are printed on top of each other and fused together

Layer by layer, the item is created – whether cladding, structural panels, or a house.

3D printing methods in construction include extrusion (involving concrete/cement, polymers, wax, and foam), powder bonding (including polymer bond, reactive bond, and sintering), and additive welding.

Advantages and Disadvantages

Like any technology, 3D printing for construction has several advantages and disadvantages. On one hand, it can be extremely fast, can reduce waste, offer greater design flexibility, and has the potential to improve job site safety. But it also requires extremely high capital costs and hard-to-find skilled labor.

ADVANTAGES

Speed
We mentioned above how Mighty Homes can build an entire house in two to three weeks, but the 3D printing element only takes around 24 hours – a heck of a lot faster than a typical framing and wall construction job. Marco Vonk of Saint-Gobain Weber Beamix says, “You save about 60% of the time on the job site and 80% in labor.”

Waste reduction
Global construction waste will reach 2.2 billion tons by 2025, a huge number that would almost double the amount of global construction waste in 2018. Because 3D printing is an additive manufacturing process, it only uses as much material as the 3D model requires without creating nearly as much waste as traditional construction processes.

Design freedom
The ability to print large structures or components from 3D models opens up design possibilities previously too onerous, expensive, or simply not possible using other techniques. Saint-Gobain Weber Beamix’s Vonk says: “3D concrete printing enables you to make any shape. You can bend it, you can make angles, you can make virtually any organic shape you want to, and it’s a one-to-one copy to what you designed on paper.”

Safety
OSHA says more than 5,000 workers died on the job in the U.S. in 2019, with around 20 percent of those fatalities in the construction industry. The nature of 3D printing means this number would almost certainly come down once the practice is more widespread.

DISADVANTAGES

Capital costs
Popular construction 3D printers cost hundreds of thousands of dollars before you even turn them on. 3D printers can be rented, but those costs are generally also high. And these costs don’t even include the electricity to power them, materials used in construction, or ongoing maintenance.

Finding skilled labor
There’s already an ongoing construction labor shortage, but things get worse when you factor in the expertise required to design 3D models and operate 3D printers – something that’s generally not a part of most construction companies’ skill sets.

Regulations and the law
The law often lags behind technological innovations, and the same is true for 3D printing in the construction industry. Most municipalities don’t have building codes that address quality standards or other regulations around 3D printing, making it difficult for a building inspector to perform accurate assessments. And there’s not much case law on the books for addressing potential problems with 3D printed buildings.

Complement your next project with Unicel Architectural

Unicel Architectural doesn’t 3D print buildings, but we’re experts at fabricating and installing highly engineered glass, timber, and aluminum building products in commercial, institutional, and residential projects. Contact us today to learn more about how we can add value to your next building project.