3D-printing in construction: where are we now?

By RICCARDO BIANCHINI

The Project Milestone 3D-printed home in Eindhoven, the Netherlands; image courtesy of 3DPRINTEDHOUSE/Project Milestone

3D-printing in construction: where are we now?

After covering the beautiful robot-made clay house designed by Mario Cucinella recently completed in Italy, we have investigated the most recent advancements of 3D printing in the construction industry.

Rather surprisingly, an unprecedented number of innovative 3D-printed buildings have been completed in 2021, despite the pandemic; apart from Cucinella’s house, they include constructions inaugurated in the Netherlands, Denmark, the United States, and Dubai. I’m not talking about prototypes or technology demonstrators, but real, permanently inhabited buildings.
Is this the dawn of an era in which bricklayers will be replaced by machines? Will we, shortly, create a house in a day with the click of a button?
Possibly.

MCA – Mario Cucinella Architects and WASP, TECLA, 3D-printed clay house,
Photo courtesy of WASP.

For the time being, I present three 3D-printed homes that have been completed in 2021, so to help you get your idea about the latest developments in this area.
All the homes were made using additive printers that deposit many thin layers of special semi-fluid concrete on top of one another.
The final result looks futuristic and primordial at the same time; more or less, all buildings are characterized by massive walls with rounded edges that vaguely resemble those of a medieval fortress. Quite frankly, none of them is particularly appealing to my eye; however, they certainly met the expectations of their owners, since they all praise the result and look pretty satisfied.

According to the developers, the main advantages of 3D printing versus traditional construction techniques are the possibility to create complex forms, a substantial reduction of construction time and costs, and replicability.
They don’t say anything about the cons; yet, I can easily predict that the main disadvantages are a limited choice of construction materials – mostly some types of plain concrete, to date – and the lack of information about durability and weather resistance.
Yet, I guess that such problems could find a solution rather soon since, for example, 3D printers for metals and polymers are already common in several manufacturing sectors, such as mechanics, and pumpable concrete mixes, similar to those used for those 3D-printed buildings, have been successfully used in construction for decades.
The main question is if new digital construction techniques will influence, and possibly improve, the way we think, design, and inhabit buildings or if they will simply replicate the selfish and narcissistic attitude of so much of the architecture of today.

Construction technique
As mentioned earlier, all three houses presented here were built using a technique in which a 3D printer creates cavity walls by depositing hundreds of layers of fluid concrete.
The printer nozzle can be supported either by a gantry crane or a robotic arm. The concrete mix must be fluid enough to be easily extruded by the nozzle but not so much to make the walls, which do not require any formwork, unstable until the concrete sets. As soon as the concrete is reasonably solidified, insulation is put into the wall cavity and tubes and wiring are fitted into previously printed technical ducts. While building the walls, the printer can also create interior elements – such as stoves, showers, and bathtubs – concurrently. It takes from 24 hours to a week to print a complete detached house.

The houses

East 17th Street Residences – Austin, Texas, United States
Though this four-dwelling residential complex designed by Logan Architecture and completed in Austin, Texas, in March 2021 is not fully 3D-printed – only the ground floors were made by a 3D concrete printer while the rest was realized with traditional techniques – it comprises the first 3D-printed homes for sale in the United States, according to its developer. Built in less than a week using an ICON Vulcan printer, the four detached houses feature from 2 to 4 bedrooms.

Weißenhorn – Beckum, Germany
Completed in May 2021 in Beckum, in the North Rhine-Westphalia region, Weißenhorn/Beckum is Germany’s first 3D-printed house ready for occupancy.
Developed by Peri, a leading German formwork and scaffold manufacturer also strongly committed to 3D construction printing, and designed by architecture and engineering firm Mense-Korte, this single-family house was almost entirely made by a BOD2 concrete printer manufactured by Danish company COBOD. It took just a few weeks for the printer, which makes about 12 square meters / 129 square feet of double-skin concrete walls in one hour, to complete the two-story, 160-sqm house.

Project Milestone – Eindhoven, The Netherlands
Project Milestone is a planned residential complex, designed by Houben / Van Mierlo Architects, comprising five 3D-printed buildings in Eindhoven, The Netherlands. To date, the first building, a single-story single-family home, was completed in April 2021. The 94-square-meter, two-bedroom house is composed of 24 large concrete elements that were printed in 120 hours in a factory nearby and then assembled on site. The house is shaped like a boulder to blend into its wooded surroundings in the Meerhoven district of Eindhoven, according to the architects. The first legally habitable 3D-printed house in Europe, the dwelling is currently inhabited by a Dutch retired couple.

Project Milestone, Eindhoven, The Netherlands, single-story 3D-printed house, exterior view; photo courtesy of 3DPRINTEDHOUSE/Project Milestone.

The interior of the house; photo courtesy of 3DPRINTEDHOUSE/Project Milestone.

Project Milestone, exterior impressions – credits: Houben /Van Mierlo Architecten. A.I: YuconVR. Photo courtesy of 3DPRINTEDHOUSE/Project Milestone.