Another question we often hear a 3D Fixtures is “Can you 3D print a house?”
While that’s not a service we offer here, it is the subject of a lot of industry interest and research. 3D printing has been used to produce architectural models since the early days. Echoing the process that has been underway for some time with other industries, the last few years have seen serious progress towards moving 3D printing from being exclusively a design tool towards use in real construction.
There are some unique opportunities involved with 3D printing buildings. In theory, a 3D printed building can be built with minimal labor – just prep the site and slot any necessary components into the holes the printer leaves for them as it builds. Organic curves and arches become as easy to make as straight lines, allowing for unique new architectural designs. Some approaches to the concept allow for the use of local materials, making the process more sustainable – and attracting interest from NASA and the European Space Agency, both of which have shown keen interest in developing the ability to 3D print structures on the Moon and Mars.
One such approach is being pursued by Enrico Dini, inventor of the D-Shape 3D printer. His device makes use of the binder-jetting strategy (see our post on the Taxonomy of 3D Printers), on a massive scale. Locally sourced sand is mixed with powdered magnesium oxide and spread into layers 5-10 mm thick – orders of magnitude larger than used by more typical 3D printers, but still allowing plenty of resolution for developing the features of a building. A printhead deposits an inorganic binding agent onto each layer to form the desired shape. The binder, magnesium oxide, and sand react together to create a solid with mechanical properties similar to that of sandstone or marble – strong enough to be used without reinforcement for some structures. It is also an ideal platform for producing sculpture, and in fact the D-Shape holds the record for the largest printed sculpture in existence – a 3x3x3 meter pavilion, titled Radiolaria, designed by Shiro Studio.
D-Shapes’ strategy is not the only one being pursued, of course. WinSun, a Shanghai based company, arguably holds the record for the largest 3D printed structure in the world. Their system works on the principle of material extrusion: A nozzle deposits a specialized aggregate material – composed of a hardening agent, sand, fiberglass, concrete, and other additives – as it traces out a path to build up the shape of the walls. By printing their design in sections and joining them with poured concrete and rebar, WinSun has been able to produce a 6 story apartment building, and they say that their process could save as much as 70% of the cost of traditional construction. There has been some controversy surrounding their system and results, however. They first came to public attention in 2014, when they claimed to have printed 10 small houses in a day with this technique. Prior to that, no one had known that they were even working on the technology, and their technique was suspiciously to that under development by the Contour Crafting project at the University of Southern California. Since WinSun’s public debut and more recent announcement of their 6-story building, 3DPrint.com has reported that according to Contour Crafting project head Dr. Khoshnevis, WinSun is not only infringing upon his patents but misrepresenting the benefits of their technique – to the point where he expects that it is neither less expensive nor more efficient or capable than more traditional methods.
Although the spectre of intellectual property theft and misrepresented costs puts a severe damper on our enthusiasm for WinSun’s claimed achievements, we have to view the overall state of 3D printed architecture as very encouraging. There are still some problems to solve before 3D printing becomes a truly viable home construction method, of course. In most areas, there are major regulatory burdens to overcome – extensive testing of materials and methods will be needed to prove that 3D printed structures are safe and reliable, and building codes will need to be modified to allow their construction. The largest demonstrations of 3D-printed architecture also still rely on prefabrication – whether due to limitations in geometry or build capacity, final structures must be assembled from smaller 3D-printed sections rather than being printed in-place with all additional components inserted during the process.
Given the degree of interest that we hear personally and the activity we see in the news, we don’t expect those hurdles to stand for too much longer. The people and projects mentioned above are hardly the only ones pursuing this goal. In Amsterdam,a team is working to print a canal house using industrial thermoplastics. Fastbrick Robotics in Australia is developing a robotic bricklayer – using cutting edge technology to implement a time-honored construction method. Given a few more years, it would be more surprising to learn that we weren’t 3D printing houses, instead of the other way around.