Collin Eaton: Traditional Buildings in the Age of Block

Graduate Student Research

Eaton_PosterThe 1976 earthquake was a defining moment in the building culture of Guatemala. Many of the nearly 23,000 deaths caused by the magnitude 7.5 earthquake were a direct result of the failure of traditional adobe and other earthen building systems to withstand the powerful seismic waves. In many cases the massive unreinforced adobe walls covered by heavy clay-tile roofs collapsed on top of their occupants. In some of the hardest hit areas like Chimaltenango, nearly 70 percent of the adobe homes were destroyed. In the wake of the event, government housing programs and nonprofit housing practitioners promoted steel-reinforced concrete block homes as the preferred, seismically-safe replacement for traditional earthen systems. Now, nearly 40 years later, concrete block homes, referred to locally as block, have become the dominant building technology in much of urban Guatemala and are increasingly expanding into the rural landscape as well.

With the goal of saving human lives, the shift toward a “culture of block” has been positive, for those who can afford it. The desire for and acceptance of block as a durable, high-quality, and seismically stable system is widespread across a range of incomes, and for many the acquisition of a block reflects an increase in social status and greater economic stability. Desire, however, is not matched by financial capacity. Manufactured materials such as block and the imported steel rebar reinforcement are subject to the fluctuating prices of the global market and the rising cost of these materials has outpaced inflation over the last decade. The result is that housing practitioners are concerned that the concrete block homes they promote are no longer affordable for their target market, or they face limitations in outreach due to rising costs. The challenge for housing practitioners in a post-1976 building culture is bridging the resulting affordability gap and addressing the disproportionate risk that results when those who can afford block homes have access to safer housing, while those who cannot remain at the mercy of the traditional building technologies available in their region.

With the generous support of a CLLAS research grant, I spent the summer of 2013 interviewing low-income housing practitioners, homeowners, and local masons in Guatemala in order to better understand the position of traditional building technology within the broader culture of building. Through an environmental lens, the lower embodied energy of traditional systems and their ability to passively regulate the climate in which they have evolved make them alluring candidates for lower-impact housing solutions. Despite my own affection for these systems, I was interested to know where they stand for those who have no other choice but to live in them, and the meaning these systems embody within the broader Guatemalan building culture. In focus group interviews conducted in Alta Verapaz, Baja Verapaz, Chimaltenango and Zacapa, I asked participants about their perceptions of traditional materials and manufactured materials, as well as their individual building strategies and material preferences. I also explored how class and indigenous identity might influence the decision of what to build. The primary goal was to understand the constraints, priorities and cost-saving potential within the building process they use—whether traditional or block—in order to help encourage a more cost-effective and inclusive culture of building, and to provide housing organizations with specific recommendations for how to bridge the risk/affordability gap.

What has emerged from the study is that the transition to a culture of block has not been universal—neither physically in the acquisition of block, nor mentally in the minds of occupants. There are many homeowners who aspire to own a block home, yet there remain many homeowners who recognize the advantages that traditional systems offer, including lower-cost, better thermal buffering, quality control in construction (and even the ability to absorb the impact of a bullet). Many participants also recognize the seismic capacity of traditional systems such as wood and bahareque while others have demonstrated the willingness to experiment with hybrid adobe systems that combine structure of concrete columns with the lower-cost and thermal buffering capacity of adobe.

Although an exploratory study, this project makes a case for reexamining the approach to low-income housing in Guatemala. On the one hand, housing organizations are responding to the demand they correctly perceive when they design and promote concrete block homes. On the other hand, there is a risk that by exclusively promoting block as the ideal material, practitioners unintentionally promote a building culture better suited to the needs of the building industry, rather than the homeowners they serve, while at the same time negating the potential of traditional systems.  The result is that the continuous advancement of traditional vernacular systems in parallel to modern materials is ruptured. Manufactured materials evolve while traditional systems are condemned to be built with the same deficiencies that lead to their failure. By bringing “modern” systems back into dialogue with traditional systems there is a potential to leverage the inherent cost savings and performance characteristics of both systems in a way that better supports traditional systems—both literally and figuratively—and, more importantly, their occupants.

This study was also generously supported with funding from the Environmental Studies Barker Award.

—Collin Eaton is a second-year master’s student in the Environmental Studies Program.  His research focuses on the ecology of building materials, traditional building systems, low-income housing and appropriate technology. He he has worked in the fields of residential construction, historic preservation, housing, and microfinance.