Behrokh Khoshnevis
University of Southern California
Los Angeles, CA

Contour Crafting (CC) is a computerized construction method that 3D prints large-scale structures directly from architectural CAD models. Walls are built up by forming their outer surfaces via extrusion of a paste-like material such as concrete, and the use of a robotic trowel to provide a smooth, contoured surface. CC is a very flexible technique, capable of constructing aesthetically pleasing “organic” curvilinear shapes as easily as “boxy” rectilinear shapes; as such, it has attracted strong interest from leading architects.

“Since the early days of 3D printing, I have been fascinated by the possibilities that these technologies could offer, so I started thinking about novel new ways to 3D print. This win is a tribute to the thousands of hours of effort it took to develop this over the past two decades. The recognition from Tech Briefs Media Group and the prestigious companies that sponsored the contest provides a valuable vote of confidence that the Contour Crafting technology is going to make an important impact on creating a better future for humanity and our planet.”
Contour Crafting is the first and only large-scale 3D printing technology that can rapidly construct complete buildings. Contour Crafting is a major innovation that automates the construction of whole structures, and radically reduces the time and cost of construction. The result would be a revolution in the construction industry that would lead to affordable construction of high-quality, low-in come housing; the rapid construction of emergency shelters; and on-demand housing in response to disasters.

The Contour Crafting technology has the following unique features:

  • Reduces construction cost to about 30% of current cost
  • Speeds up the construction process by a factor of at least 50
  • Reduces construction injuries and fatalities (400,000 and 6,000 per year, respectively, in the US, and more severe in developing countries)
  • Provides emergency shelter to the more than 37 million annual victims of war and natural disasters
  • Provides dignified housing to the low-income population of the world
  • CC eliminates construction waste, as the computer precisely adds material where it is needed
  • Dramatically reduces construction energy usage (by 90%) and CO2 emission (by 70%)
  • Promises limitless architectural features such as curved walls
  • CC is ideal for lunar and Martian construction using in-situ resources

During the past decade and under academic grants, the inventors have demonstrated the feasibility of the concept and currently have a system that can build 400-square-foot structures with solid core or corrugated core walls. Within two years, with sufficient investment, it should be possible to demonstrate 24-hour automated construction of a full 2500-square-foot structure. A lightweight machine that will be easily deployable also will be built.

The optimal outcomes will be at short-term and long-term levels. In the short term, successful testing of the specimen structures built by the technology to prove that they outperform alternative manual on-site and prefab construction methods (wood frame, brick, concrete, etc.) will be ideal. Various performance criteria such as strength, cost, speed, waste, energy consumption, thermal insulation, weight, etc. will be measured by standard techniques (such as compressive and tensile strength testing, life cycle analysis, cost analysis, etc.).

The ultimate long-term outcome is the revolutionizing of the construction industry. As for demand, according to the United Nations, there is a worldwide shortage of 800 million houses. Massive construction of low-income housing around the world, rapid response to large-scale disasters by providing dignified shelters, and significant positive impact on the environment and energy shortage are some of the impacts of CC.

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