By Erica Avrami

The wealth of the world's earthen architectural heritage runs the spectrum from entire cities to monumental sites to intricate decorated surfaces. The range and complexity of earthen architectural materials, the variety of sites and environments, and the diversity of possible treatments make conserving this heritage a considerable challenge. Many organizations and individuals are striving to meet this challenge through various field, research, and educational activities.

Since the late 1980s, the International Centre for Earth Construction-School of Architecture of Grenoble (CRATerre-EAG), the International Centre for the Study of the Preservation and Restoration of Cultural Property (ICCROM), and the Getty Conservation Institute have collaborated on issues related to earthen architecture conservation. In 1997 they formalized this collaboration with the establishment of Project Terra.

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The mission of Project Terra is to foster the development of earthen architecture conservation as a science, a field of study, a professional practice, and a social endeavor. Through cooperative activities in the areas of research, education, planning, and advocacy, the project members seek to advance the field in a variety of ways.

An important aspect of this initiative is its focus on pervasive issues in the field, rather than on the preservation of specific sites. The majority of organizations in the world dealing with conservation are regional, national, or local authorities and nonprofit organizations that are charged with or devoted to the care of heritage resources—collections, buildings, and sites—within their jurisdiction. CRATerre-EAG, ICCROM, and the GCI are all international institutions that do not carry this responsibility. The flexibility afforded by their mandates allows for a broader and more pioneering approach to the needs of the field.

Activities undertaken through Project Terra are designed to advance understanding, policy, and practice in various aspects of earthen architecture conservation, rather than to address site-specific problems or interventions. For example, the January 2001 Shelters Colloquium in Arizona—organized in cooperation with Project Terra—did not focus on the shelter needs of specific earthen sites. Rather, it used individual cases as a way to address broader issues related to sheltering and to encourage a more integrated approach to—and evaluation of—shelters for archaeological sites.

As in the case of the Shelters Colloquium, the primary Terra partners—CRATerre-EAG, ICCROM, and the GCI—collaborate with other organizations to undertake particular activities that support both the Terra goals of addressing the broad needs of the field and the often more site—or region—specific goals of associated partners. An example of this collaboration is Project Terra's involvement in the recently completed management plan for the site of Chan Chan in Peru. The Peruvian authorities charged with the long-term care of the 9th- to 15th-century earthen remains of Chan Chan wanted to develop a comprehensive plan for the future of the site, while the Terra partners were interested in promoting integrated planning for earthen heritage resources. By disseminating the methodologies and results of the Chan Chan planning process, Terra hopes to encourage others to develop similar strategies for earthen sites and historic centers. This type of cooperation can also serve to empower local or regional authorities to deal with their conservation issues in a more proactive and integrated way.

Education Efforts

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Earthen architecture and its conservation are, on the whole, not well represented in academia. Viewed all too often—and erroneously—as a substandard building material, earth is largely absent from courses on construction technology, design, architectural history, and preservation. Traditionally, the conservation field has responded to this deficiency by organizing short courses related to the preservation of earthen architectural heritage—courses that emphasize the continuity of the tradition of building with earth. The Pan-American Courses on the Conservation and Management of Earthen Architectural and Archaeological Heritage, known as the PAT courses—organized first by CRATerre-EAG and ICCROM in France and then by CRATerre-EAG, ICCROM, the GCI, and the Instituto Nacional de Cultura in Peru—were a series of such short courses, launched in 1989.

PAT99—offered in late 1999 and organized under the auspices of Project Terra—was the last of the short-term, midcareer PAT courses. The 10-year PAT experience trained many professionals, helped connect those working in the field, and provided an "incubator" for didactic materials and methods in the teaching of earthen architecture conservation.

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A primary educational objective of Project Terra is to develop earthen architecture conservation as a field of study at the university level. After the completion of PAT99, the project partners felt that the time was ripe to apply the experiences of PAT to working with institutions of higher learning to establish formal, long-term courses related to earthen architecture and its conservation. The Terra partners are now communicating with interested universities to explore possibilities for collaboration.

That work is being done in conjunction with the UNESCO Chair on Earthen Architecture, Constructive Cultures, and Sustainable Development—an educational program (not a professorship) formally inaugurated in 1998. The UNESCO Chair is based at CRATerre-EAG, which has a long record of university and professional training in the field. In its program, the Chair addresses the need for training from three perspectives: improving conditions of housing constructed with earth, utilizing resources more effectively, and promoting the value of earthen architectural heritage and traditions of building with earth. CRATerre-EAG initiated the work of the Chair by promoting the development of educational programs in new earthen construction—from the housing and resource perspectives—among a growing network of universities and training institutions.

The UNESCO Chair program and the Project Terra partners have launched a joint program called the Terra Consortium. The consortium is conceived as a vehicle for incorporating curricula related to earthen architecture conservation into existing university programs. Specifically, the consortium seeks to promote the development of additional education in the conservation of earthen architectural heritage and earthen building traditions. The Project Terra partners are collectively responsible for identifying institutional partners, coordinating the network/consortium, fostering the development of specific programs, and facilitating the exchange of information and ideas among collaborators. The Terra Consortium aims to develop educational initiatives that embed earthen architecture into existing programs of study dealing with the conservation of the built environment, whether through additional courses, certificates of specialization, postgraduate degrees, or the like. Institutional partners in the consortium will have the opportunity to collaborate with one another, as well as with the Terra partners, in the ongoing evolution of their respective initiatives.

Proposals from interested institutions are being received, and the Terra organizations are evaluating potential collaborations and negotiating with university partners. Through cooperation on the development of curricula, didactic materials, and faculty, the consortium of universities and training institutions addressing the conservation of earthen architecture is expected to grow.

Work in Research

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The research component of Terra has also developed over the past couple of years, with a more concentrated effort now under way.

In 1998 a research survey polled scientists and practitioners about perceived research needs in the field and endeavored to identify current research initiatives. The survey was undertaken as a follow-up to the Gaia Research Index, which involved a similar survey in 1992.

In 1999, a review of the research literature began under the auspices of Terra to determine, through the literature, the trends and gaps in earthen architecture conservation research over the past 15 to 20 years. Hubert Guillaud of CRATerre-EAG undertook an initial review, and in the next phase additional colleagues from the field will explore further various themes and topics. This multiphase effort will be compiled and synthesized. The literature review is scheduled for completion before the end of this year.

The Terra partners recognize the challenges posed by the rather limited research base for earthen architecture and its conservation—in particular, research regarding the behavior of earthen materials, components, and structures. Improved understanding of why and how earthen architecture deteriorates would enable the field to make better conservation decisions in the long term and would ultimately help establish the conservation of earthen architecture as a science.

With this in mind, the Terra partners have sought to foster a dialogue among their colleagues about potential areas of investigation. In May 2000—immediately following the Eighth International Conference on the Study and Conservation of Earthen Architecture, held in Torquay, England—Project Terra, in cooperation with English Heritage, hosted a meeting to discuss research needs in the field of earthen architecture conservation (see Conservation, vol. 15, no. 2). A summary report of the meeting's discussions and recommendations is available in the Conservation section of the Getty Web site.

The priorities and recommendations outlined in the report reflect a process of hypothesizing about the field that, in many instances, extends beyond the traditional boundaries of earthen architecture conservation. This pushing of boundaries requires an ongoing dialogue between those working with earthen architecture and other professionals in related disciplines, in order to define the needs and opportunities for research, as well as to refine specific research questions.

The Project Terra partners are committed to fostering dialogue and to facilitating research collaboration. Some initial steps include:

  • As mentioned previously, the Terra partners are coordinating a critical review of research literature related to earthen architecture conservation. The review is expected to be completed in 2001.

  • CRATerre-EAG, in collaboration with ICCROM and the GCI, is initiating a dialogue on the development and expansion of existing soil classification systems, used by industry, in order to better meet the needs of earthen architecture conservation.

  • CRATerre-EAG, in collaboration with ICCROM and the GCI, is fostering a continued dialogue and potential research collaboration on the binding mechanisms of earthen materials as they relate to earthen architecture conservation. To initiate this effort, a preliminary meeting was held at CRATerre-EAG in early December 2000.

  • Ancillary to the initiative on binding mechanisms mentioned above, the GCI, in collaboration with CRATerre-EAG and ICCROM, is initiating cooperative research on the deterioration mechanism of earthen architecture.

  • The GCI and the Museum of New Mexico State Monuments are currently undertaking an evaluation of amended mixtures and conservation treatments tested during research efforts at the site of Ft. Selden, New Mexico. The report on phase one of these is available in the Conservation section of the Getty Web site.

The above-mentioned initiatives are just some of the activities of Project Terra and represent an even smaller portion of the many endeavors worldwide to protect our earthen architectural heritage and to promote continuity of the tradition of building with earth. The overall development of the field of earthen architecture conservation is an ongoing pursuit on the part of many. The Project Terra partners are hopeful that by leveraging their own institutional resources—and by collaborating with additional organizations and individuals—they can significantly contribute to the growing interest in earthen architecture and the increasing efforts to protect this heritage found throughout the world.

Erica Avrami, GCI project specialist, serves as the Institute's project manager for Project Terra.

For more information about Project Terra and for links to the CRATerre-EAG and ICCROM partner sites, please visit: Project Terra