Reviewed by Lexie CornerJan 27 2025
A study published in Construction and Building Materials by researchers at the Massachusetts Institute of Technology (MIT) proposes using lightly treated mud, including soil from construction sites, as "formwork" molds for casting concrete.
“What’s cool here is we’re able to make shape-optimized building elements for the same amount of time and energy it would take to make rectilinear building elements,” says Sandy Curth (standing in the back). Image Credit: Saleh Jamsheer
The method offers a potential cost-saving alternative to traditional formwork materials in concrete construction. By using locally sourced mud, this approach could streamline construction processes, reduce expenses, and lower carbon emissions associated with traditional construction materials.
What we have demonstrated is that we can essentially take the ground we are standing on, or waste soil from a construction site, and transform it into accurate, highly complex, and flexible formwork for customized concrete structures.
Sandy Curth, Ph.D. Student, Department of Architecture, Massachusetts Institute of Technology
“It has the potential for immediate impact and does not require changing the nature of the construction industry,” stated Curth, Director of the Programmable Mud Initiative and co-author of the study.
The research was conducted by a team of 10 authors, including MIT students Natalie Pearl, Emily Wissemann, Tim Cousin, Latifa Alkhayat, Vincent Jackow, Keith Lee, and Oliver Moldow, as well as Mohamed Ismail from the University of Virginia. Caitlin Mueller, Associate Professor in MIT's Departments of Architecture and Civil and Environmental Engineering, and Lawrence Sass, Professor and Chair of the Computation Group in the Department of Architecture, were the study's senior co-authors. Sass is also Curth’s graduate advisor.
Building a Structure Once, Not Twice
Building with wooden formwork is both costly and time-intensive. In practice, constructing concrete structures often requires two steps: building the wooden framework and then pouring concrete into these forms.
Using soil as formwork offers an alternative to this process. While soil may seem unconventional compared to the strength of wooden formwork, it is sufficiently durable to support poured concrete.
The EarthWorks method incorporates additives such as straw and applies a wax-like coating to the soil material to prevent water loss from the concrete. With large-scale 3D printing, the researchers can transform construction site soil into custom-designed formwork structures.
“What we have done is make a system where we are using what is largely straightforward, large-scale 3D printing technology, and making it highly functional for the material. We found a way to make formwork that is infinitely recyclable—it’s just dirt,” Curth added.
Beyond the availability and cost of materials, the method offers two key advantages. First, it has environmental benefits. Concrete construction accounts for up to 8 % of global carbon emissions. This approach reduces emissions by using recyclable formwork and enabling precise molding to minimize excess concrete usage.
By applying a form optimization process, previously developed for reinforced concrete by Ismail and Mueller, the carbon emissions associated with concrete structural frames can be reduced by more than 50 %.
The EarthWorks technique brings these complex, optimized structures much closer to built reality by offering a low-cost, low-carbon fabrication technique for formwork that can be deployed anywhere in the world.
Caitlin Mueller, Associate Professor, Department of Architecture and Civil and Environmental Engineering, Massachusetts Institute of Technology
“It is an enabling technology to make reinforced concrete buildings much, much more materially efficient, which has a direct impact on global carbon emissions,” Curth added.
In general, EarthWorks technology makes it easier for architects and engineers to design unique concrete shapes due to the flexibility of the formwork material. Molding concrete with soil rather than wood makes it easier to cast in unique shapes.
Curth added, “What is cool here is we are able to make shape-optimized building elements for the same amount of time and energy it would take to make rectilinear building elements.”
Group Project
Curth highlights the collaborative nature of the Programmable Mud group’s work, noting the significant contributions of Sass, a pioneer in computational methods for low-cost housing, and Mueller, who applies computational approaches to explore innovative structural designs in architecture.
“Concrete is a wonderful material when it is used thoughtfully and efficiently, which is inherently connected to how it is shaped. However, the minimal forms that emerge from optimization are at odds with conventional construction logics. It is very exciting to advance a technique that subverts this supposed tradeoff, showing that performance-driven complexity can be achieved with low carbon emissions and low cost,” Mueller added.
While pursuing his doctorate at MIT, Curth founded FORMA Systems to bring the EarthWorks method to the construction industry. The method requires the use of large on-site 3D printers, but Curth points out that significant savings in material costs can offset the equipment requirements.
Curth envisions applications for the technique in constructing templates for two-story residential buildings entirely made from earth. While adobe construction is already widely practiced in countries like the United States, the goal is to automate and scale such processes while maintaining affordability.
Curth sees potential in using soil either as a mold for concrete or as a primary construction material.
Curth concluded, “People have built with earth for as long as we have had buildings, but given contemporary demands for urban concrete buildings, this approach basically decouples cost from complexity. I guarantee you we can start to make higher-performance buildings for less money.”
The project received support from the Sidara Urban Research Seed Fund, administered by MIT’s Leventhal Center for Advanced Urbanism.
Journal Reference:
Curth, A., et. al. (2024) EarthWorks: Zero waste 3D printed earthen formwork for shape-optimized, reinforced concrete construction. Construction and Building Materials. doi.org/10.1016/j.conbuildmat.2024.138387