Preserving Modern Architecture: What, Why, Where, and How?

by Theodore H.M. Prudon, FAIA
excerpted from Preservation of Modern Architecture

Summary: The basic process for determining what Modern buildings to preserve is similar to the one used for more traditional buildings (although the pertinent criteria are more complex). One fundamental difference, however, is that selections for preservation can be made ahead of time: the most important and significant properties can be identified now. As best as possible, the Modern building stock can then be protected, rather than waiting until time and change diminish it so that choices about what to preserve must be made from what remains.

The sheer quantity of resources, coupled with the relative youth of buildings often not yet recognized as historic, present unprecedented challenges. This article examines some of the existing mechanisms used by preservationists to identify and assess the building stock that makes up Modern architecture.

Current preservation process: assessing significance and integrity
The generally accepted process for managing the historic built environment consists of several distinct steps: setting criteria defining what is worthy of preservation, conducting a survey to locate and document those resources to be saved, evaluating the resources found in the survey against the earlier established criteria, giving those works that qualify some sort of official status or recognition, and, finally, following up with protective measures. This process can be as general as the national and international preservation framework, for which a comprehensive survey process is not feasible. That framework generally recognizes buildings and sites with associations to important events or persons of high artistic or technological merit. The selection process is then based on nominations that are accepted and evaluated against established general standards. The process can also be specific, as for a historic district, where the criteria for evaluation depend on the history of that geographic location and where a survey of each building is possible so that a comparative analysis can be completed. The overall process for determining what resources must be brought to bear becomes complex.

Conferring official recognition is usually based on two elements: significance and integrity. A building’s significance and its overall integrity are the basis for conveying official recognition and designation whether locally, regionally, nationally, or internationally. That recognition may result in even more positive and active forms of protection. Assessing significance—that is, identifying those elements of a building or site that make it more important than others and thus worthy of protection—relies on a historic narrative that places the property in an architectural, historical, social, and cultural context. In essence, a case must be made that the building or site is worthy of preservation. Historically, the significance of a building or site is established by its uniqueness: that it is rare, special, or the last or best of its kind. This value system, which establishes peerlessness—to some extent merely the result of survival—as an important signpost of significance thus allows one-of-a-kind status to become a selection criterion almost by default. A value system based on singularity remains applicable to the iconic buildings of Modern architecture, but the preservation field has expanded its mandate to include broader criteria and assessments for significance beyond age and rarity.

Additionally, the field has incorporated groups of buildings, different building types and sites, and cultural landscapes—whether geographically contiguous, such as neighborhoods, or in some other thematically related form. This thematic relationship may involve individual structures that are grouped together as a collection because of their social, cultural, historic, architectural, or technical significance. Alternatively, each structure may not be of iconic significance individually but may be noteworthy collectively. Where the significance is in the collectivity, the entire group can be designated following standard preservation processes. Where each and every one of the structures is important, then a process to select the most important ones within the theme can, if necessary, be established.

The integrity of the structure—that is, its ability to convey its significance—also needs to be assessed to make an informed decision about its preservation. Unlike determining significance, which is largely based on historical and documentary analyses, assessing integrity deals with what physically remains and its relative condition. In general, for a structure or site to retain its integrity, considerable portions of the original structure as it relates to its relative significance must be intact and in its original location; just how much will vary depending on location and culture.

When this general process for determining significance and assessing integrity is applied to the preservation of Modern architecture, and when it is applied to other kinds of architecture, some major differences occur. Compared with older, more traditional buildings and sites, three factors make the determination of significance for Modern architecture richer, but also more complex:

1. Far more buildings, structures, and sites have been created in recent times than ever before in history, and a far more comprehensive comparative analysis is therefore required to determine which buildings and structures are the most significant. We should not rely on time and nature to make the selections.
2. For more recent buildings and sites, a far larger quantity of primary design and construction documentation is available, covering both the specific building processes and the period itself.
3. Because a building’s design and construction are still within recent memory, participants in that process—family, friends, colleagues, contractors, and tradespeople—may still be active. They may be able to offer information and opinions, making oral history an important and integral part of the documentation and evaluation process in a way that has not been possible previously.

And this complexity also affects the assessment of integrity. In the assessment of more traditional buildings, the amount of original fabric remaining has been emphasized either related to its original construction or its period of significance. Integrity has concerned itself largely with material authenticity. For the assessment of more contemporary structures, the assessment criteria have to be expanded to include a broader definition of authenticity and the concept of design intent. It is not just how much remains of the original material that is important, but how much of the original design is recognizable and visually cohesive as well.

Determining significance
Making the case for the significance of Modern buildings has remained a challenge in three aspects: the quantity of buildings and sites that have to be considered (and that is expanding at an unprecedented rate), the still-developing scholarly documentation and research, and the public recognition and acceptance of the significance of this heritage. A few examples will illustrate the scope and magnitude of this challenge. In the United States, of the buildings extant today, more than 75 percent were constructed after World War II, while in the United Kingdom, where war did serious damage and intense reconstruction followed, more than 80 percent of the total building stock dates from the 20th century, with more than half of it constructed after 1950.

Although preservation organizations and the general public have increasingly supported the preservation of Modern architecture beyond the icons since the mid-1990s, doubt about just how significant this heritage is does remain. This ambivalence is due, in part, to how recent the period in question is, and to the ubiquity of seemingly similar buildings, which contributes to the perception of a lack of their importance and reduces the sense of urgency about their preservation. Memories so current, buildings so young, and criteria for preservation that equate uniqueness with significance make it challenging to quantify and defend Modern buildings even at the first step of the standard preservation process. Established notions of the importance of age to the consideration of a building or site as architectural heritage in the U.S. can vary from none in Chicago to 30 years in New York to 50 years—the accepted age for listing on the National Register of Historic Places. Even where age limits are established, buildings or sites considered to be of exceptional significance are sometimes exempted and can be included in designations, although this happens only rarely. Particularly when considering a recent building, the term significant is often used rather than historic to avoid the association with the age factor and to acknowledge that a building’s importance can relate to more than just the date of its original construction.

Reflecting the eligibility reasoning in many national and international guidelines, the U.S. criteria for evaluating historic properties for listing districts, sites, buildings, structures, and objects on the National Register note that they should represent a quality of significance in U.S. history, architecture, archeology, engineering, and culture that possesses integrity of location, design, setting, materials, workmanship, feeling, and association that includes association with significant historical events or with the lives of significant persons. Although Modern buildings will likely meet one or more of these general criteria, these traditional definitions of significance have been expanded by, for instance, DOCOMOMO and others, with such considerations as innovation—whether in aesthetic, social, or technical terms—as a way to represent better the value of Modern architecture. Thus, the assessment of significance and eligibility takes into consideration the prevalence of technical and social innovations embraced by architects of the period.

The quantity of buildings also creates the very practical dilemma of how to study, analyze, and determine what to save. Even as research and academic scholarship grows, not enough of that scholarship has found its way into easily accessible sources or the preservation literature to aid in establishing the historic context and significance criteria to be applied to the first step of the standard preservation process. For that purpose, one of the most frequently used tools in tackling the recent building stock is the theme or thematic study—essentially a comparative analysis of data used to arrive at a hierarchy of significance and a basis for decision making.

Comparative analytic studies are a well-accepted scientific method for analyzing and categorizing large quantities of data and assessing their merit. Such studies examine a group of buildings based on a specific commonality, be it a theme, subject, typology, trend, period, or geography, to develop the historic narrative or collective statement of significance that not only places buildings in an overall historical context but in the architectural, social, and cultural framework of a particular period or development as well. Similar to the more detailed, more limited historic narrative that is part of the significance statement for an individual structure, the theme study generates an understanding of a group of buildings, and, while comparable to a significance statement for a historic district, it may be more general in nature, broader in scope, and apply to multiple geographic areas.

(Ed note: the third topic of Identification and Documentation: Thematic Surveys by Topic and Theme is covered extensively in Chapter 5 of Preservation of Modern Architecture.)

Conclusion
Although the process and sequence of the acts of preservation have largely remained the same, identification, evaluation, the scope of the types and the number of buildings, as well as the overall materiality all have shifted emphasis in the process of selection, designation, and protection. The need for comprehensive survey, documentation, and comparative evaluations has never been greater. Fortunately, many local and regional initiatives have begun to address these needs. However, the importance of surveys lies not only in their process but also in how the information is organized and used in preservation, zoning, and planning in the context of overall development.

Whereas significance and the justification for preservation can be argued to a large degree on the basis of existing criteria or the interpretation thereof, the relationship among integrity, design intent, and authenticity as it relates to Modern architecture is as yet largely unexplored and remains to a large degree subjective. Clearly, the balance among these three fundamental elements is one that needs to be considered carefully and extensively in the future.

Copyright 2008 John Wiley & Sons, Inc. Reprinted with permission from John Wiley & Sons, Inc.