How Does 3D Printing Homes Work, And Why Should We Even Consider It?

An artist’s digital rendering of a house being 3D printed.

Throughout history, manual labor has always been used for constructing houses and other infrastructure. However, this may at least partially change with 3D printing technology, which uses an automated process to create structures layer by layer. This new technology has caught the attention of many because it could help address housing shortages, lower costs, and reduce waste. More significantly, it could reduce the need for human input in construction or potentially even get rid of it altogether. The process of using 3D printing to build homes involves large printers that deposit materials like concrete to form walls and other parts of a house. 

Before construction even starts, a computer program is typically used to create a digital design, which acts as a blueprint that guides the 3D printer on where to place materials. In traditional construction, workers manually control the process and do much of building a house. 3D printing, on the other hand, automates a lot of the tedious work, thus eliminating the need for a lot of workers. A large printer, which can sometimes be as big as a house itself, moves along tracks or a robotic arm, and it squeezes out material in precise layers. Although you may have only seen plastic being used in 3D printing, concrete is actually the most common material, at least for “printing” infrastructure, because it’s strong and easy to work with. Some projects, however, use other materials like plastic or clay. The printer builds the structure from the ground up, and based on the digital design, it creates walls, floors, and even curved shapes that would be hard to make with regular methods.

But why build a house with 3D printing, especially when the traditional process already works fine? Well, one of the greatest benefits is speed. While building a small house utilizing a traditional construction process might take a few weeks, the same project could be 3D printed in a matter of days. For instance, a company in Texas printed a 500-square-foot house in just about 24 hours! This speed can primarily be attributed to the fact that automated systems do not need breaks. The printer operates continuously, laying down material until the structure is complete. This speed could come in particularly handy after natural disasters or in fast-growing cities. The technology isn’t perfect though, as finishing touches like windows, doors, electricals, and plumbing still require human workers, which adds time to the process.

Cost is also another advantage. 3D printing reduces the need for labor, which is a big part of traditional construction expenses. According to data from Bridgit, labor can account for 20%, or sometimes as much as 40%, of total construction costs. Fewer workers mean less money spent, and the materials used, like concrete, are often cheaper than wood or steel. Some estimates suggest 3D-printed homes can cost 20-30% less than standard houses. In places with high housing prices, this could make homes more affordable for families. 

The expected growth of the 3D printing construction market from 2025 to 2034.

The technology also produces less waste than traditional methods. In regular construction, extra materials like cut wood or unused bricks often end up in landfills. 3D printing uses only what’s needed, as the printer deposits material precisely according to the design. This lack of wastage is appealing to those in support of sustainability, especially since construction accounts for a lot of global waste. In fact, some projects experiment with recycled materials, like plastic or rubble, to make the process even more environmentally friendly. For example, at Technische Universität Berlin in Germany, researchers tested a mix of concrete and recycled soda-lime glass to 3D print wall elements and prefab blocks for a building. Not only were they able to recycle glass successfully, they also achieved good insulation and strength without much extra processing!

Despite these benefits, challenges remain. The size of 3D printers limits what they can build because most are only designed for small or medium houses. In addition, the printers need to be moved to the site, which can be difficult in remote areas or places with rough terrain. Weather also affects the process, as rain or extreme temperatures can interfere with the materials hardening properly. In Austin, Texas, rain and cold weather in the fall of 2018 led to a months-long delay for a 3D-printed housing project by ICON. This was because the rain and cold weather prevented the concrete from setting properly, and although researchers are working on solutions for such issues, they continue to slow down widespread use as of now.

This 3D printing technology is already being used in real projects. In the Netherlands, Project Milestone in Eindhoven’s Bosrijk neighborhood, a collaboration between the Municipality of Eindhoven, Eindhoven University of Technology, Saint-Gobain Weber Beamix, and Van Wijnen, built five boulder-shaped, 3D-printed concrete rental homes. The first one was completed in 2021, where residents Elize Lutz and Harrie Dekkers moved in. On the other side, in Mexico, the nonprofit New Story partnered with ICON to construct a community of 50 single-story, 500-square-foot homes in Tabasco for low-income families, with each house printed in roughly 24 hours using a mobile Vulcan II printer. 

3D printing technology isn’t a full replacement for traditional construction yet. It really only works well for simple structures, and it’s currently infeasible for 3D printing to be used for complex buildings with multiple stories or intricate designs. Even when 3D printing is utilized, human workers are still needed for tasks like installing electrical systems, plumbing, and finishing interiors. But as the technology improves, automation could handle more parts of the process and therefore reduce reliance on manual labor. For now though, it’s simply a tool that complements existing methods, offering a faster and cheaper way to build basic homes.