JAIC 1993, Volume 32, Number 1, Article 2 (pp. 15 to 21)
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Journal of the American Institute for Conservation
JAIC 1993, Volume 32, Number 1, Article 2 (pp. 15 to 21)



ABSTRACT—The conservation of immovable cultural property—outdoor monuments, buildings, archaeological sites, and landscapes—is a relatively recent profession, yet one that has grown out of earlier 19th-century restoration theories. Although part of the broader conservation context, architectural conservation presents unique problems due to the issues of context, immobility, size, scale, and complexity of use and materials. These issues are examined with respect to established standards for the examination, documentation, and treatment of traditional historic and artistic works.

The first major attempt in North America to establish a dialogue between fine arts conservators and professionals involved in the preservation of historic structures and sites occurred at a conference in Williamsburg and Philadelphia in 1972 (Timmons 1976). The aim and outcome of that conference was to initiate contact among curators and conservators responsible for the care of traditional artistic and historic works and the many diverse professionals involved in the preservation of outdoor monuments, buildings, landscapes, and archaeological sites. Now, after 20 years of continued professional activity and the development of several graduate and postgraduate curricula in architectural conservation,1 the creation of the Architecture Specialty Group within the American Institute for Conservation of Historic and Artistic Works signals a long overdue professional collaboration and maturation of both fields.

The establishment of general principles for the conservation of historic structures and sites is a 20th-century phenomenon, but the principles derive largely from conflicting European restoration theories of the 19th century (Tschudi-Madsen 1976). One school of thought, exemplified by the writings and work of Eugene Emmanuel Viollet-le-Duc, held restoration as “a necessary reestablishment in a finished state [of that] which may in fact never have actually existed at any given time”(Viollet-le-Duc 1980, 195). This notion of restoration as a means of reestablishing stylistic unity was strongly opposed by the English writers and theorists John Ruskin and William Morris, who advocated the total preservation of a building's physical history as cultural memory. They held restoration that resulted in falsification as “the worst of all destructions” (Ruskin 1988, 184). This controversy was partially reconciled in this century through the work and writings of Camillo Boito, Cesare Brandi, and other modern European theorists who attempted to establish universal principles and standards. Many of these form the basis for our conservation charters today (Brandi 1977).

The identification of what is culturally significant and therefore worthy of preservation has always been difficult. But perhaps it is even more so now, as we witness the rapid disappearance of once-common cultural traditions and landscapes almost overnight. Today broader definitions of significance allow many examples of cultural property from diverse times, places, and cultural groups to be considered for preservation.2 These broader definitions should help to create a more universal, long-lived model different from models of the past that displayed a preference, for example, for the preservation of Gothic buildings in 19th-century Europe or colonial buildings in the United States.

What makes the building arts, including landscape, different from other works that have traditionally come under the rubric of cultural property? The building arts, more than any other form of material culture, are intrinsically site oriented. We now use the term “immoveable cultural property” to describe the many kinds of artistic and historic works, such as buildings, engineering structures, monuments, landscapes, and archaeological ruins, that possess a unique relationship to their site.

This relationship to site causes tremendous problems in the conservation of immovable cultural property. As the environment cannot be easily controlled, such property can suffer physical degradation from atmospheric pollution, misuse, or obsolescence and vandalism from social and economic changes. In the case of the building arts, the desire and the need to preserve, wherever possible, the contextual relationship creates a whole series of requirements and restrictions sometimes at odds with conservation solutions commonplace for museum collections. In addition to the problems of physical context and lack of environmental control, conservation of the building arts is more difficult on account of size, complexity, and continuing use.

While significant conservation issues are best dealt with in terms of a country's or group's own cultural traditions, established conservation principles expressed through the various charters and standards of representative organizations can guide intervention. All cultural property should be regarded as subject to these basic standards, but that is not to imply that these standards can and should be satisfied in the same way for all forms of cultural patrimony. The need for a conceptual framework arises specifically because of the numerous theoretical approaches possible in the intervention of a diverse range of historic monuments and sites.

The American Institute for Conservation's Code of Ethics and Standards of Practice, drafted in 1967 and 1963 respectively and both revised in 1979, are now under review and revision. Other charters such as the International Charter for the Conservation and Restoration of Monuments and Sites (Venice Charter) of 1964, revised in 1978, and the Australia ICOMOS Charter for the Conservation of Places of Cultural Significance (Burra Charter) of 1981, revised in 1988, were written specifically for the conservation of historic monuments and places of cultural significance. Despite their differences, all these documents identify the conservation process as one governed by absolute respect for the aesthetic, historic, and physical integrity of the object or place by a high sense of moral responsibility (AIC 1979, code I and IIA; UNESCO 1978, 1, 3, 9; Australia ICOMOS 1988, 2–3).

In any profession, a code of ethics dictates the accepted rules or standards governing the conduct of members of that profession. Moral responsibility compels members of the profession to act in accordance with those standards for proper professional conduct. What, then, are the standards that have been developed to guide the intervention of all cultural property as found in the numerous conservation charters? Summarized from the more recent documents, they fall into the following categories:

  • the obligation to perform research and documentation, that is, to record physical, archival, and other evidence before and after any intervention to generate and safeguard knowledge of the site (AIC 1979, standards I; UNESCO 1978, 9–10; ICOMOS 1988, 23–24);
  • the obligation to respect “Alterswert” or cumulative age-value, that is, to acknowledge the site or work as a cumulative physical record of human activity embodying cultural values, materials, and techniques (AIC 1979, code IIA 1979; UNESCO 1978, 3, 11; Australia ICOMOS 1988);
  • the obligation to safeguard authenticity, that curious quality so critical to the mental and visual enjoyment and appreciation of historic works (AIC 1979 code IIF, standards IID; UNESCO 1978, 9, 12; Australian ICOMOS 1988, 3, 14);
  • the obligation to perform minimum reintegration, that is, to reestablish structural, aesthetic, and semiotic legibility with the least interference (AIC 1979, code IIF; UNESCO 1978, 9; Australia ICOMOS 1988, 3); and
  • the obligation to perform interventions that will allow other options and further treatment in the future (AIC 1979, code IIE). This principle recently has been redefined more accurately as “retreatibility” (Appelbaum 1987), a concept of considerable significance for architecture and outdoor monuments given their need for long-term high-performance solutions, often structural in nature.

In addition to the standards prepared for the treatment of cultural property, other standards have been established in some of the above documents governing professional relationships and relationships between conservators and their clients.

As summarized in the “Definitions” and “Conservation Principles” of the Burra Charter, the ultimate aim of in situ conservation is to retain or recover the cultural significance of the place. In situ conservation must include provision for its security and maintenance and for its future. Conservation is based, first and foremost, on a respect for the existing fabric; it should involve the least possible physical intervention. It should not distort the material evidence, especially as that evidence reveals traces of additions and alterations of history and use. The conservation policy appropriate to a place must first be determined by an understanding of its cultural significance and its physical condition. The conservation policy should determine which uses are compatible, not the other way around.

Out of 19th-century restoration controversies and a growing awareness of modern conservation theory as developed for the fine arts, architectural conservation has emerged today as a scientific discipline focused on the physical context of the present structure or site and its particular conditions of aging and survival. The concept favors a thorough methodological approach: studying, documenting, and diagnosing the quantitative and qualitative processes of deterioration and change but always from a fixed point of reference—the building itself. Intervention is minimal but opportune. It is conducted with experimentally determined and proven techniques and avoids the subjective renewal of structures and their materials.

This last point is important, as it leaves open for discussion the possibility for more drastic interventions, including the reinstallation or replication of missing or damaged components such as a roof or protective exterior stucco. Aside from securing visual and aesthetic reintegration, these replacements become even more critical if they sustain or improve the future performance or life of the structure in its environment. Obviously changing or controlling the environment either by building a protective enclosure on site or by relocating the work, often indoors, are options that allow maximum protection with minimal impact to the actual physical fabric. Such interventions do, however, affect the context, a feature already discussed as significant for many such sites.3

Since much of what has been built over time has its basis in functional as well as artistic requirements, a traditional approach to conservation is often advocated; whereby any intervention is conducted as part of the normal use and repair of the structure. This approach, although admirable in its simplicity, ignores the fact that as recognized cultural property, these sites are now different, divorced from their past by the present's historical consciousness, and that consciousness dictates new motives and methods for their use and preservation (Brandi 1977). In addition, rapid changes over the past century in building technology and architectural education and practice have made it difficult for architects to know how to treat older buildings. Some building technologies have totally disappeared. This problem is becoming all-too-painfully clear as we now tackle the conservation of recent architectural masterworks of the 20th century. It is not unlike the situation artists found themselves in at the beginning of this century, when they sought to restore easel paintings but traditional materials and techniques were no longer available or known. Architects trained as modern designers often have little of the technical or theoretical information necessary to understand the design, technology, and behavior of traditional materials and structures. Moreover, many materials and skills, once commonly employed in traditional buildings, are no longer available or feasible due to requirements of time, cost, and skill level, and to associated health hazards.

The ethical and practical dilemmas surrounding the conservation of immovable cultural property defy easy solution, as there is often more than one alternative (Beale 1985). Several options can satisfy the standards already laid down by the various charters for the conservation of cultural property. Choosing among them requires knowledge of these standards and the historical basis for their creation.

The degree to which conservation principles are applied depends on the status of the site, but they must be applied to avoid the short-lived conceits of changing taste and unproven technology. More often than not, the long-term failure of many architectural conservation projects has been caused by improper attitudes and approaches rather than the inability to find appropriate technical solutions.

The problem of integrating established conservation principles into the care and restoration or even reuse of historic structures and sites is compounded by the fact that the architectural conservator generally is not involved firsthand in the planning, execution, or review of the proposed intervention. Most construction projects involve architects, engineers, specification writers, general contractors, and tradesmen, and the professional and legal structure of such projects is complex. Decisions involving the selection and extent of any given conservation treatment as well as the actual execution of those treatments are often not made by a trained conservator. Even project development, site supervision, and approval of specialized conservation work, from documentation to remedial treatments, may take place without a professional conservator on the project team.4

Conservation practice presumes an understanding of the intent of designers, builders, or users and of the effects of time and human use on that work. Conservation practice, moreover, assumes a knowledge of the treatments necessary to preserve and reintegrate that work in compliance with the principles established. Artistic replication or reconstruction, sometimes necessary to reestablish visual appearance and meaning, can involve skills of a very different nature and should neither replace nor compete with the original work or the conservation process. In the case of the decorative arts, and in particular the building arts where architectural surfaces may have decorative features, this distinction can easily become confused, the misunderstanding often centering around artistic ability and re-creation instead of conservation.

Historic monuments and sites are complex artifacts that depend on the legibility and authenticity of their components for meaning and appreciation. To treat these components as less important replaceable features only reduces the historical significance of the whole. As early as 1821 Giuseppe Valadier proved the validity of such an approach by incorporating subtle yet distinguishable repairs in his restoration of the Arch of Titus in Rome (Erder 1986).

Today such concerns are often eclipsed by careless or indifferent attitudes that result in heavy-handed and irreversible solutions. Time, expense, impracticality, and the desire to change or improve often work against methodical study, documentation, and the saving of original fabric. But in reality failures in architectural conservation are often the result of poor planning, a lack of trained professionals, and the difficulty of getting those involved to accept a weather-worn surface or the uneasy truth that few treatments are forever and all require continual cyclical maintenance.

The basic principles outlined in the various charters and codes for the conservation of all cultural property are not the sole responsibility of any one professional group. They apply instead to all those involved in the preservation of cultural property and represent general standards of approach and methodology. If the preservation of historic monuments, buildings, and sites is to continue to develop as a serious and professional discipline, it must embrace and apply the principles already established. To achieve this end, training and education in conservation ethics and practice must be encouraged and professional roles supported.


1. Over the past 25 years, training in architectural conservation has grown from programs developed for midcareer professionals such as those at the International Centre for the Study of the Preservation and Restoration of Cultural Property (ICCROM), begun in 1965–66, and the Institute in Advanced Architectural Studies at the University of York, begun in 1971, to university graduate programs with a specialization in technical conservation such as those at the University of Pennsylvania and Columbia University (ICCROM 1983).

2. Significance may be defined categorically by values. These include associative or symbolic value, informational value, aesthetic value, and economic value. (Lipe 1988)

3. Such approaches have been adopted over time with varying degrees of success, especially for ruins and archaeological sites protected beneath or within shelters, such as Casa Grande, Arizona, and Piazza Armerina, Sicily, Italy, or relocated monuments such as Abu Simbel, Egypt, and the horses of San Marco, Venice, Italy (Stubbs 1984).

4. In 1980, the title architectural conservator was officially adopted by the North Atlantic Region of the National Park Service as a recognized position distinct from historical architect and exhibit specialist.


AIC. 1979. Code of ethics and standards of practice. 1967, 1963. Washington, D.C.: American Institute for Conservation of Historic and Artistic Works.

Appelbaum, B.1987. Criteria for treatment: Reversibility. Journal of the American Institute for Conservation26:65–73.

Australia ICOMOS. 1988. Australia ICOMOS charter for the conservation of places of cultural significance (Burra Charter). 1981.

Beale, A.1985. The varying role of the conservator in the care of outdoor monuments: Ethical dilemmas. In Sculptural monuments in an outdoor environment, ed.V.Naud�. Philadelphia: Pennsylvania Academy of the Fine Arts. 39–50.

Brandi, C.1977. Teoria del restauro.Torino: Giulio Einaudi.

Erder, C.1986. Our architectural heritage: From consciousness to conservation.Paris: United Nations Educational, Scientific, and Cultural Organization.

ICCROM. 1983. International meeting of coordinators of training in architectural conservation. Rome: International Centre for the Study of the Preservation and the Restoration of Cultural Property.

Lipe, W.1978. Value and meaning in cultural resources. In Material culture and the study of American life, ed.I.Quimby. New York: W. W. Norton. 1–10.

Ruskin, J.1988. The lamp of memory. In The seven lamps of architecure.1849. Reprint. New York: Farrar, Straus, and Giroux.

Stubbs, J. 1984. Protection and presentation of excavated structures. In Conservation on archaeological excavations, ed.N. P. StanleyPrice. Rome: International Centre for the Study of the Preservation and Restoration of Cultural Property. 79–89.

Timmons, S., ed.1976. Preservation and conservation: Principles and practices.Washington, D.C.: Preservation Press.

Tschudi-Madsen, S.1976. Restoration and anti-restoration.Oslo: Universiters Forlaget.

UNESCO. 1978. International charter for the conservation and restoration of monuments and sites (Venice Charter). 1964. In Erder 1986.

Viollet-le-Duc, E. E.1980. The foundations of architecture.1854. Trans. K.D. Whitehead. New York: George Braziller.


FRANK G. MATERO is an associate professor of architecture in the Graduate Program in Historic Preservation of the University of Pennsylvania and director of the Architectural Conservation Laboratory. He is also a lecturer at the International Centre for the Study of the Preservation and Restoration of Cultural Property (ICCROM) in Rome. From 1981 to 1990 he was assistant professor of architecture and from 1985 director of the Center for Preservation Research in the Graduate School of Architecture, Planning and Preservation of Columbia University. He received his M.S. from the Graduate School of Architecture, Planning and Preservation of Columbia University in 1978 and attended the certificate program in conservation at the Conservation Center at the Institute of Fine Arts, New York University, from 1981 to 1984. His teaching and research are focused on the history of building technology and the conservation of historic building materials, in particular on stone and architectural surface finishes. He is a professional associate of the American Institute for Conservation of Historic and Artistic Works and a member of the Advisory Committee of the International Masonry Institute. Address: Graduate Program in Historic Preservation, 115 Meyerson Hall, University of Pennsylvania, Philadelphia, Pa. 19104–6311.

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Copyright � 1993 American Institute for Conservation of Historic and Artistic Works