Conservation is changing.
Between 1945 and 1980, roughly as much was built globally as had been constructed throughout all prior history. Compounding this unprecedented magnitude of construction, the rise of modern architecture through the course of the 20th century fostered many ways of building that fundamentally changed both the nature and the cyclic frequency of material and system renewal that we have come to anticipate in working with ‘traditional’ means of construction. At the same time, new formal and material paradigms led in many cases – particularly in the 1960s and 1970s – to the construction of large housing, commercial and civic works that – in addition to posing new technical conservation challenges – were often underappreciated by a large portion of the using public.
Recognition of these issues within the design and preservation communities has been building for over a quarter of a century, and we are now at a pivotal point in addressing how to continue to sharpen and formulate strategies to reinvigorate the various typologies and ‘isms’ that characterize the structures and component systems of mid-late 20th century heritage.
Two particularly wide reaching questions demand our attention. The first is addressing programmatic and economic obsolescence: many modern buildings were tightly designed to a very specific set of criteria that may no longer have relevant Use Value (I will use Riegl’s classification of values throughout the essay) or meet regulatory standards. The second is addressing the persistent negative perception of these resources by both users of the property and the public (Fig. 1). While fashion has embraced the best of these buildings and public resistance – particularly among younger constituencies – may also be softening, resolving these issues might nonetheless necessitate a degree of change that falls outside accepted norms (as developed through documents such as the Athens, Venice and Burra Charters, and the Nara Document on Authenticity).
Addressing modernism begins with a fundamental question: are there conceptual and physical differences in modern architecture that consequently change the philosophy toward its treatment?
Two key characteristics that distinguish a lot of modern properties are the impermanence of many modern materials and systems, and the fact that many buildings were planned or financed to enable or even encourage a service life of only 20-30 years. In different ways these both reflect the inherent dynamism in modernism, and the rapidly accelerating pace of change that came about with the emergence of the modern world.
A new conservation paradigm began to emerge in the 1990s that acknowledges the notion of modernism’s ephemerality and consequently foregrounds sustaining the idea of the building or site, even if many of the materials themselves – some experimental or untested – cannot be saved. This in turn has led some practitioners to become far more amenable to the replacement of original fabric than is normally tolerated in the canon of western conservation practice. Beginning at this time (initially within DOCOMOMO), a lively dialogue began to emerge about how to dovetail this new paradigm with the existing conservation standards and charters, which were developed to provide methodical, nominally objective criteria for treating historic properties.
Concurrently, we have been developing ever more sophisticated means of conserving original modern materials and systems. Considerable research has been done particularly on the development of repair materials and technologies that enable the conservation of materials such as architectural concrete and complex systems such as metal and glass window wall and curtain wall systems. This is a field that of necessity will continue to grow in order to continue to improve approaches to conserving these systems, but also to address the wide range of synthetic materials that have become a part of modern and contemporary construction.
The JAC focuses on understanding and developing conservation solutions to the myriad technical challenges that confront those entrusted with the care and maintenance of the built environment. In this issue, dedicated to the conservation of modern resources – or “Renewing Modernism” – we also hope to address broader concerns such as those that accompany the whole idea of ‘reuse’ – how to achieve interventions that appear seamless (at best inevitable), the accommodation of contemporary program uses, building code, accessibility and other regulatory requirements, and the need to improve both energy performance and resilience in all structures. The inevitabilities of change of use, and the increasing expectations of owners and users, dictate that we also address the broader issues of user comfort and perception if we are to ensure the survival of much of the heritage of the recent past.
Our present goal through this journal issue is to clarify and illuminate; to identify and close gaps in knowledge and understanding, and - over time - to bolster the technical and philosophical armature that has been constructed by organizations such as the Association for Preservation Technology (APT), DOCOMOMO, ICOMOS ISC on 20th Century Heritage, Historic England, the Center for Historic Buildings at the United States General Services Administration (GSA) and the Getty Conserving Modern Architecture Initiative (CMAI). The materials gathered together here we hope will serve as an incremental step in this effort.
The papers in this issue have been adapted from material presented at a seminal APT conference on Renewing Modernism, held in Kansas City in November 2015, for which I was one of the organizers. We specifically called on participants to look beyond the “icons” – the formative Modern buildings which have already received so much philosophical and technical expertise, in the manner accorded to older buildings of high significance – and to address sustainable solutions that can improve the performance, comfort and curb appeal of modern properties of mainstream value – also referred to as Ordinary Everyday Modernism, or OEM.
These ordinary buildings (including in Britain many that are listed Grade II) are typically serviceable structures in need of general refurbishment, and they constitute the vast majority of modern resources. Our objective coming out of Kansas City, and the focus again of this collection of papers, was to identify ideas, strategies and methods that would enable properties which might otherwise have been demolished or unsympathetically altered to be refurbished in ways that would benefit their owners and users and the environment, all without loss of essential character and by extension, significance.
Our task is therefore to address three issues. The first is provide an appropriate framework within which to identify the social, cultural and economic value of the building, to ensure that we have the criteria needed for evaluation as well as for deciding the best approach to their rehabilitation. This means facilitating a balance between formal and material conservation, and the need for appropriate but robust change. The second involves mastering the technical challenges themselves, which often means the development of resilient, sustainable material assemblies and processes that both preserve character and increase performance.
The third issue is in some ways the most difficult and complex. It is no secret that much of the corpus of modern architecture remains intractably unloved – even by many who otherwise appreciate and admire modernism. While conservation or preservation are often dubbed the management of change, the means that must be taken to address this issue in many modern properties often involves a degree of change that makes many in the conservation community quite uncomfortable, as it perhaps speaks to an approach that, in its emphasis on the design of interventions goes too far away from the idea of restoring the inherent qualities of an historic property. This is an issue of performance and perception – it addresses sustainability as both as a function of energy conservation, and as doing what is necessary for the building to remain whole and valuable.
It is important to note that this can be challenging even with some buildings that are generally agreed by the design and preservation communities to be of the great importance. For example, Louis Kahn’s Richards Laboratories at the University of Pennsylvania (a building of international architectural significance) had to be repurposed and re-thought on the interior, to overcome many irreconcilable problems regarding its persistent inability to perform the function for which it was originally designed.
What was acceptable 50 or more years ago in terms of buildings standards and user expectations is very different today, and building owners are often skeptical that many older buildings can be successfully refurbished to meet these standards. As John Allen pointedly observed in his keynote address to the 2012 DOCOMOMO conference in Helsinki, for the vast majority of rehabilitation projects, treating the resource as “heritage” is well down the list of concerns for the building owner, and indeed it is only something that they are comfortable discussing once they are confident that all the technical and functional issues have been addressed.
Many of us have faced these situations where heritage concerns must be worked in “through the back door.” Outside of work for government agencies specifically concerned with historic properties or for the museum world, the common touchstones that must first be addressed are efficiency, performance, curb appeal and comfort– in other words, modernization rather than preservation. This is above all a creative challenge. It very quickly involves program questions such as defining an appropriate use for a building whose original function has lapsed, or design challenges when a building must be “refreshed”. Meaningful adaptive re-use often involves a search for the right program to fit an existing building. Modern architecture characteristically promoted a ‘tight-fit’ of plan to original program, and changing codes, contemporary space use standards and program requirements often compromise the ability of these structures to continue to function for their original purpose.
The correct, complementary language must be developed for every intervention. While this may arguably be an area that blurs the boundaries of responsibility in the minds of many conservation professionals, it is nonetheless an important consideration in contemporary practice.
How do the papers given here address these issues? We begin with looking at how to address the fundamental question of adaptability, which means the task of fitting relevant, appropriate program to an historic resource:
Jack Pyburn looks at the evolution of the programming process and reimagines how it should function when being tailored to a historic structure, where ‘repurpose to accommodate the building’ has become a common mantra. It is at this juncture that values based preservation has particular resonance. A typical repurposing analysis will look at metrics such as floor area, structural bay sizes and floor to floor heights to predetermine the suitability of an asset to accommodate a specific program type. But in analyzing possible new uses for a given structure, the application of values based principles that look at the full panoply of historic and cultural assets bound up with a given structure, becomes particularly important. There is generally higher tolerance for this kind of approach, which limits owner flexibility, when working with assets of greater significance or unique configuration, such as high bay spaces, or the multiple tower layout found again in Kahn’s Richards Labs, but there is also every reason to be able to apply it across a wide range of resources.
The two examples cited by Jack at the Georgia Institute of Technology deal with buildings of perhaps middling architectural significance, but great cultural value to the institution and – in one instance – to the history of science and technology. The best solutions arise through the application of a broader range of values to help best determine the most appropriate fit of program to space within these structures.
Theo Prudon then follows with a paper that importantly reminds us of the incredible diversity of the heritage of the recent past, and presents some of the complex technical and physical issues to be addressed as we rehabilitate the legacy of post and late modernism, right up to considering what is currently being built today. Theo’s point is that whatever we may call or think of much of the architectural production of the last 50 years, beyond the polemical differences inherent in these works lie many common and often intractable technical issues that must be addressed in the value context of those principles that generated the original work.
Mark Brandt brings in the broad sustainability argument with a short essay that outlines the larger case for the general renewal of the built environment of the recent past in the name of reducing carbon footprint. He cites the growing trends toward renovation and creative re-use, leveraging the embodied energy in what is already built. He particularly calls upon those within the design and preservation communities to lead this effort through our examples as professionals who have mastered the management of change and can thus point the way to intelligent, sustainable solutions to the adaptation of these resources.
The papers that address technical challenges begin with Deborah Slaton’s overview of the unique characteristics and technical and philosophical pitfalls of dealing with a wide range of modern materials. One particularly intriguing topic is the notion as to whether some of these synthetic or composite materials develop a patina that might add to or at least not diminish their value – the assumption being that for the most part these materials do not age gracefully – as Newness Value and the nature of how the deterioration typically manifests itself trump whatever Age Value may be inherent in the weathered artifact. This bears closer scrutiny and should be looked at with an especially critical eye, for there are materials like stainless steel, concrete and even composite materials such as Kalwall, a sandwich panel utilizing translucent fiberglass sheets over an aluminum frame, whose change over time can be managed in such a way that there is a luster in the aged material that imparts legitimate, acceptable change to the asset.
Two papers address the first sets of comparative case studies that demonstrate the reasons for and value in a multi-tier approach for the evaluation and treatment of the icons vs. OEM. The paper by Wessel de Jonge, one of the founders of DOCOMOMO, briefly discusses the restoration of two iconic early modern works, the Zonnestraal Sanitorium and the Van Nelle Factory, both in the Netherlands, noting the compromises in performance necessary to enable the retention of key character defining features. He then contrasts this with the more robust approach taken in adapting several important but lower tier structures to new uses, which prioritize economics, energy performance and function without ignoring heritage values. He closes with summary recommendations cached as lessons learned that have arisen out his own work and can be used as guidelines or principles for working on modern properties in general.
Michael McClelland’s paper presents a very lucid comparative analysis of the strategies employed to balance choices favoring pure conservation in a Grade one listed Mies van der Rohe complex versus interpretive design of replacements for failed or inadequate original material in the name of pragmatism and economy in a less significant apartment building by architect Uno Prii. His conclusions capture in more detail the importance of rigorous analysis and classification of character defining features in forging consensus as to what constitutes acceptable change.
Geoff Rich then follows with a discussion of Feilden Clegg Bradley (FCB) Studios’ refurbishment of the Southbank Centre in London, and the renovation and large addition to the Students Union building at the University of Bristol. Both projects focus highly on sustainable solutions that are designed to improve energy performance of the buildings, but in the case of Bristol, there is also a much larger functional need and the explicit desire on the part of the client for a “new look” that informs their solution – making it much more evident as a work of contemporary architecture than one of the 1960s or ‘70s. This is the kind of choice we often face if we are to save structures like this at all – it is conservation in the environmental rather than the architectural sense; limiting the use of new materials and conserving the embodied energy of the original work.
Z. Smith closes the issue with a data-rich, emphatic return to the greater environmental concerns, beginning with an overview of many of the specific technical issues to be addressed when trying to increase both the resilience and the sustainability quotient of typical mid-century modern commercial structures. In particular, he demonstrates how different metrics such as the Energy Use Index (EUI) can be used to prove the worth of rehabilitating modern structures, countering the argument of many who would argue that their demolition and replacement with new high performance buildings is the more sustainable solution. The importance of this cannot be overstated, as it gives scientific weight to the argument that there is long term sustainable value in rehabilitation.
He then focuses on two examples in Louisiana – one a significant structure by Skidmore, Owings and Merrill (SOM) in New Orleans, and one of lesser significance – where some of the environmental priorities and deterioration patterns will vary from cooler climates, noting as in our other examples the varying degrees of change that can appropriately be realized based upon the original quality and condition of the building. The SOM building is sympathetically modernized on the interior but most of the work on the exterior is virtually invisible, while meeting current regulatory standards. The second work, a very plain modern structure in Baton Rouge, is given a radical internal transformation – which is only hinted at on the building’s exterior – whose example serves as a model for how invigorate, enhance and sustain this kind of OEM without appreciably changing its public face.
What does all of this mean for the broad range of design and conservation professionals faced with the rehabilitation of this vat building stock.? Perhaps first it means a willingness to step back and contemplate the full range of social, economic and environmental values that are potentially embodied in even the most ordinary modern resources, and then to understand how to formulate balanced solutions infused with a conservation ethos. In OEM, the significance is typically lower and the need for change is readily accepted and can thus be accommodated more easily than in an iconic work.
This dichotomy points up another distinction in working with modern heritage. When preparing even an iconic traditional building for a contemporary function there is an inevitable, necessary overlay of the full panoply of building services that must be integrated into the historic fabric to enable its continued function. There are however many equally iconic modern works in which building services are an integral, character defining part of the original design and there is consequently less tolerance to allow them to change in any way that may alter the appearance of the work. In addition, some of these designs were conceived as a gesamkunstwerk where furnishings and equipment for the building were an integral part of the original idea and realization of the building. These works typically deserve, and where possible receive, meticulous conservation treatment at a level of detail that is perhaps even more comprehensive – in terms of often being invested in the most minute details of the fabric – than what is typical for the restoration of a traditional building that is being prepared for contemporary use.
However, these are comparatively rare instances when measured against the volume of rehabilitation work we face today, and while they must be (and increasingly are) properly addressed, the larger goal will be to achieve and maintain a balanced, pragmatic approach that weighs conservation against all of the ‘real-world’ uses, regulatory and performance issues that are outlined herein. Such an approach will help determine to what degree they should to be treated as heritage, and to what degree their treatment as heritage becomes a point for negotiation in pursuit of durable, sustainable and economically viable transformation. The most salient example of the value of this kind of approach is perhaps the clear articulation of how much embodied energy can be saved through rehabilitation rather than replacement.
It is equally important that we find compelling ways to communicate these values to those entrusted with maintaining, transforming and ultimately sustaining these properties into the future. Whether it is the story of the building’s architect, engineer or patron, its link to historic events, or even its character as a manifestation of a particularly engaging aspect of high or popular culture; the importance of constructing a compelling narrative about the resource as a component part of the assessment cannot be overlooked.
This approach demands flexibility in taking a values-based approach to understanding and evaluating the building and site, including creativity and leadership guiding the development of the philosophical and technical means necessary to successfully accomplish change of this magnitude without robbing these resources of their essential character defining features. As architects, conservators, engineers, scientists and planners, we are first and foremost charged with finding and promoting the best means to conserve and restore historic structures; but when we are dealing with properties requiring robust change to ensure their survival, it is equally incumbent upon us to both draw from and contribute to the larger intellectual and creative dialogue that will enable positive outcomes.
It is our hope that the ideas and examples discussed in this issue of the JAC will raise as many questions as they purport to solve, but in doing so will provide a meaningful contribution to the dialogue on how best to address the renewal of the vast, complex inventory of the built environment of the recent past.
 Alois Riegl: The Modern Cult of Monuments: Its Character and Origins, 1902; reprinted in Oppositions 25: Monument/Memory (New York, Rizzoli, 1982)
 Historic England: Conservation Principles, Policies and Guidance: https://content.historicengland.org.uk/images-books/publications/conservation-principles-sustainable-management-historic-environment/conservationprinciplespoliciesguidanceapr08web.pdf/
 John Allen: From Sentiment to Science; Docomomo Comes of Age, keynote address given at 12th Docomomo International Conference, Helsinki, Finland, August, 2012.