Yifeng Jiang, Carlos Pimienta
Prof. Ronald Rael
ARCH 269

Raúl Ramírez created the CINVA-Ram press in 1956 at the Centro Interamericano de Vivienda in Bogotá as a response to growing housing shortages in Latin America, developing a construction method that could be easily used by local communities to provide cost-effective housing for economically disadvantaged populations. This project rethinks material culture in architecture by shifting attention away from resource-intensive and exclusionary construction systems toward locally sourced, low-carbon, and community-empowering alternatives. At the center of the research is the compressed earth block, or CEB, understood not only as a building unit but as a social, ecological, and architectural tool. Produced through a CINVA-Ram press, the blocks demonstrate how simple fabrication methods can transform available soil into durable masonry components with reduced dependence on industrial materials, long-distance transportation, and specialized labor.

The wooden CINVA-Ram press developed for the project becomes an essential part of this investigation. Rather than treating construction as a distant industrial process, the press makes material production visible, tactile, and accessible. Its assembly reveals a low-tech but precise system of compression, leverage, and repeatability, allowing earth to be shaped into consistent blocks through a process that can be learned and reproduced by local communities. In this way, the project positions fabrication as both a design exercise and an act of empowerment, where residents and builders can participate directly in the making of their own built environment.

The hexagonal compressed earth blocks extend this research from production to architectural performance. When assembled into a porous wall, the blocks create a patterned system of mass, shadow, ventilation, and enclosure. The geometry allows the wall to function as more than a barrier, it becomes a breathable and climate-responsive surface. Its openings can filter light, encourage air movement, and create visual depth while maintaining the thermal mass and material character of earth construction. The alternating tones and rough textures of the blocks further express the natural variability of the soil, emphasizing the beauty of an imperfect, site-specific material.

Through the design, fabrication, and assembly of the CINVA-Ram press and prototype wall systems, the project argues for an architecture rooted in material responsibility and social resilience. Compressed earth blocks offer a viable alternative for vulnerable regions where conventional building systems may be too expensive, carbon-intensive, or inaccessible. By combining low-skill construction, local material sourcing, and climate-appropriate performance, the project proposes a more equitable model of building—one in which architecture becomes a means of ecological repair and community self-determination.

Caleb Adams, Fernanda Loyola Cardoso and Isabelle de Metz

The project begins with an exploration of the Kiln Tower for the Brickworks Museum by Boltshauser Architekten. Designed as a contemporary reinterpretation of the site’s industrial heritage, the tower serves as both a landmark and an exhibition structure for the museum. Our interest, however, focused specifically on how the project investigates rammed earth as a contemporary structural system through prefabrication and vertical prestressing. 

More specifically, the tower utilizes steel tension rods to compress stacked earthen blocks, transforming them into a 9-meter-high, earthquake-resistant structure. By placing the earthen elements in constant compression, the system overcomes earth’s inherent weakness in tension while enabling a tall, stable, and fully reversable building assembly.

In an attempt to parallel the intricacy of this construction system, our team sought to create an earthen, modular prototype of the tower to explore the possibilities of earth and its compressive strength. To achieve this, our team began by experimenting with mixtures of three key ingredients earth, clay, and sand, using different ratios to produce bricks measuring 3”x4”x6” inches. A wooden formwork system was first constructed, along with a hand-made ramming tool fabricated from plywood to begin ramming the earth together. The proportions of the earth, clay, and sand were varied as the bricks were layered vertically in order to create visible striations throughout the assembly. 

Next, we cut plywood rectangles matching the exact dimensions of the bricks to sandwich the central units together. Additional plywood plates, extending one inch beyond the top and bottom bricks, were then added to cap the assembly. Five bricks were stacked vertically, allowing us to drill a #10 tension rod through the entire length of the prototype. Tension was then achieved by tightening a nut and washer at the top of the rod, compressing the stacked earthen blocks together and replicating the prestressing strategy used in the original tower.

The final prototype successfully stacks five compressed earth blocks, demonstrating the structural viability of the prestressing strategy. The assembly can serve as both a vertical wall and horizontal ceiling/lintel condition. Our investigation turned towards its potential as a ceiling or lintel element, since achieving horizontal spans in earthen construction is a known difficulty due to the material’s poor tensile performance. We tested the model as a simple beam supported at two end points, and as a double cantilever supported in the center, and observed how the prestressed compression allows the earth to resist gravity loads that would have otherwise caused failure.

This study establishes a foundation for further investigations and possibilities of this novel system. There could be further testing of the module’s maximum load, determining the ideal span to depth ratios. Beyond the individual module, there’s an opportunity to explore how these modules could interlock adjacently to form a seamless ceiling or floor diaphragm. The tie rods could potentially pass through the bricks, or the plywood end plates elements might be redesigned to serve as structural joinery.

Finally, the long-term interaction between the wood, metal, and earth offers a compelling study in differential weathering. The accelerated erosion of earthen components will affect the tension of the steel rods, and together with the slower erosion of the wooden plates may affect the strength of the overall system over time. However, the different rates of erosion may create beautiful aesthetic contrasts. 

Group Member: Yuxin Chen & Yufan Jiang

This project explores the potential of compressed earth blocks as an experimental architectural material infused with organic waste additives.

Inspired by the textured earthen surfaces of the Beijing Teahouse by Kooo Architects, the research began with testing different types of tea leaves and later expanded to include coffee grounds and plant fibers as additional material components.

Through a series of hand-crafted molds and compression tests, the study investigates how these organic materials influence the color, texture, density, strength, and tactile qualities of soil bricks.

Beyond material testing, the project also explored the architectural application of the bricks through the fabrication of a full-scale 1:1 prototype and a 1:4 mock-up model. These models were used to study brick geometries, assembly methods, and the spatial and atmospheric potential of the material as an interior wall finish.

By combining waste materials with traditional earth construction techniques, the project examines new possibilities for sustainable material reuse while emphasizing the relationship between craft, material experimentation, and architectural atmosphere.

Dachverband Lehm is a German-based organization, established in 1992, specializing in earthen construction, particularly the use of rammed earth (Lehm in German) as a modern, sustainable building material. The company focuses on reviving traditional earth-building techniques while integrating contemporary engineering and architectural practices. Based in Germany, Dachverband Lehm works closely with architects, designers, and builders to create structurally sound and aesthetically refined rammed earth walls for residential, cultural, and commercial projects.

The organization emphasizes the environmental benefits of earth construction, including low embodied energy, recyclability, and the use of locally sourced materials. Their work demonstrates how rammed earth can meet modern building standards while maintaining a strong connection to natural materials and regional identity.

Dachverband Lehm maintains an extensive online resource through their website, earthbuilding.info. The site offers comprehensive information on traditional and contemporary earthen construction techniques, material selection, and design considerations. It also features educational content, including training programs, workshops, and vocational courses for professionals and enthusiasts interested in sustainable building practices. Visitors can explore international research initiatives, case studies, and examples of earth architecture, along with guidelines, standards, and regulatory information that support the safe and effective use of rammed earth in modern construction.

Following the spread of Buddhism, Shikkui was first introduced to Japan from the Korean Peninsula in the 6th century.  The original purpose was to provide a canvas for religious paintings.  When Shikkui was first introduced to Japan, paper fibers were mostly likely used in place of hemp.

Traditionally, the manufacturing of lime was energy intensive and lime was a valuable commodity in pre-industrial Japan.  Therefore, it was used very sparingly.  The Shikkui lime finish is usually applied a few millimeter thick over an earthen plaster, and in some cases, over a sand-lime plaster.  It’s primary function is to protect earthen plastered walls from rain erosion.  Depending on exposure, the lifespan of a Shikkui lime plaster is about 20 years. In this sense, it is a kind of sacrificial layer protecting a bamboo lattice and earthen plastered wall that will last over one-hundred years.

Shikkui was developed to allow large, uninterrupted earthen walls to be finished without joints. That is, by improving workability and moisture retention, Shikkui allows for the walls of castles and earthen store houses to be finished without interruption, so there are no joints in the finish lime plaster.

Through a chemical reaction with the carbon dioxide in the air, hydrated lime returns to limestone and provides a recalcitrant, weather resistant and dust free finish.

Seaweed glue is added to improve workability, that is, increase moisture retention and delay setup so that the plaster can be worked longer. (Seaweed glues are also added in earth plasters for the same reason.) Traditionally, dried seaweed was boiled and strained to produce glue, but now a powdered form is commonly available.

Fine hemp fibers reduce cracking and allow for a thin application.
Recipes vary according to the season (temperature and humidity) and craftsperson.

The following is a basic recipe for a Shikkui:
Hydrated Lime 20-23Kg (approx. 44-50lbs)
Powdered Tsunomata Seaweed Glue 500-1000g
Hemp Fibers 400-800g

Nakazaki Residence in Setouchi, Okayama, is an excellent example of exquisite craftsmanship, including fine plastering. Built over a period of 10 plus years during the early 1900’s, Nakazaki residence features traditional Japanese architecture with early western influences.

Nakazaki Residence in Setouchi, Okayama, is an excellent example of exquisite craftsmanship, including fine plastering. Built over a period of 10 plus years during the early 1900’s, Nakazaki residence features traditional Japanese architecture with early western influences.

The defining characteristic of plastering in Kyoto is the use of color clays.  The Kansai area of Japan is blessed with a variety of colored clays and these where incorporated into earthen plasters hundreds of years ago.

https://japaneseplastering.blogspot.com/

https://www.japaneseplastering.com/fundamentals/japanese-finishes