While South Africa has some catching up to do, the use of 3D printers in the local design and construction industry is steadily gaining traction – and could even pose some interesting social dilemmas in future.

In an era of increasing technological disruption, the global architecture and construction industry faces its own threats to the status quo. Few of these have a greater capacity to shake up the way buildings are conceptualised, designed and constructed than 3D printing.

“It was first developed in the 1980s, but at that time was a difficult and expensive operation and so had few applications. It is only since 2000 that it has become relatively straightforward and affordable,” explains UK-based online resource for the construction industry Designing Buildings Wiki.

The technology has also evolved for application in the construction industry. A 3D scanner or computer-aided design programme is used to create a 3D digital model of the item, which is then read by the computer. The computer uses a 3D construction printer to lay down successive layers of whichever printing medium has been selected – be it liquid, powder, sheet material, plastic or concrete. These layers fuse to create the item.

Currently, the use of 3D printers in the South African construction industry is limited and extends chiefly to the printing of 3D plastic construction models by architects and building developers. The printer allows firms to present tangible, interactive prototypes with details and designs to clients, rather than simply discussing a 2D drawing.

The technology was first introduced into universities in the 2000s and saw students using 3D printing in various design projects. It has since filtered into use in forward-thinking local firms for “rapid prototyping”, as Jaco Jonker, candidate architect at Paragon Architects, says.

Certain manufacturing and design firms have also started to employ 3D printing in theproduction of smaller design elements, such as chairs, lights, moulds, glazing brackets, thresholds, and experimental ironmongery.

Fellow Paragon Architects candidate architect, Francois Mercer, describes the local uptake of the technology as “decent”, despite only one South African firm – Morgan 3D Printers – having thus far developed a bespoke local technology offering.

The sustainability question

The environmental impact of 3D printing in the construction industry remains largely untested. Technology proponents argue that 3D printing houses saves on transport and emission costs but the environmental impact of 3D printing often does not take into account the impact of the manufacture and development of the technology itself.

Sustainability questions are largely dependent on the material used during the printing process. The printed prototypes are normally non-recyclable plastics, while more traditional building materials, such as concrete, are used during the printing of the building itself.

Global progress

Internationally, 3D printing in construction is progressing and has evolved beyond simple prototyping. Several global examples using the technology exist, including Shanghai firm WinSun Decoration Design Engineering, which has used large 3D printers to spray a mixture of quick-drying cement and recycled raw materials.

The system fabricates blocks off site by layering the cement mix in a diagonally reinforced pattern before the blocks are assembled on site. The company believes this method will one day be used to build large houses and skyscrapers.

In Spain, a group of construction and design specialists, led by the Institute of Advanced Architecture of Catalonia (IAAC), has successfully constructed the world’s first micro-refined concrete 3D-printed pedestrian bridge. The structure, printed off site and installed in a park in Madrid earlier this year, is 12m long and 1.75m wide, and is the first time that 3D printing technology was used in the field of civil engineering for a public space.

A house in a day

An impressive global example of the potential of 3D printing in the construction industry came in December 2016, when San Francisco-based start-up Apis Cor successfully printed a 38m2 house at the company’s test facility in the town of Stupino, Russia, in less than 24 hours.

The printing of load-bearing walls, partitions and the building envelope was fully automated. Apis Cor’s proprietary 3D printing technology, which was developed by company CEO and founder Nikita Chen-iun-tai, comprises a construction 3D printer, a mobile automated concrete mix and supply unit, design and printing software, a control programme, and a dry mixture storage silo.

Resembling the arm of a tower crane, the printer is able to rotate around its axis, which means it is compact, whereas usually a printer would need to be larger than the object it is printing. Only two people are required to oversee the process. The printer uses a concrete mix to produce the house.

As the printer prints self-bearing walls and partitions, it is up to 70% cheaper than houses built using low-cost construction blocks (both in terms of the material costs and the speed of construction).

The final construction cost of the printed house amounted to $10 134, or around $275/m2 (approximately R3600/m2).

The South African context

Three-dimensional printing of houses in South Africa – despite the creeping housing backlog – is a far more nuanced debate. As Mercer points out, employment considerations need to be taken into account with the introduction of any new technology that potentially threatens jobs.

Jonker is similarly emphatic that the 3D printing of buildings cannot viably be followed in South Africa, lobbying instead for a combination of 3D printing technology with vernacular construction techniques to create a hybrid product.

Additionally, Mercer cautions that, from an architectural perspective, there is a risk that building with robotics for efficiency will encourage a “copy-paste” approach that could sterilise the country’s built environment.

Should 3D printing reach this point, government would find itself having to regulate a fledging industry with little legal precedent.

Jonker, meanwhile, reaffirms that 3D printing technology provides a means for those across the built environment value chain to easily manufacture complex geometry that would otherwise be impossible to construct using more traditional methods.

By Natalie Greve

See earthworks magazine issue 40 October-November 2017 for the full feature.