The Mediating Wall
In an effort to overcome the difficult separation of the theories of disjunction and stylistic unity, a method must evolve to fulfill the needs of both. Separation must be established between the new and old buildings immediately adjacent to one another but, at the same time, the new must also integrate within the context of the greater surrounding environment which may extend far beyond the building's own volume. This synthesis can be accommodated through the metaphor of the mediating wall, an element perceivable as either a physical object or a suggested image. The sources for the mediating wall primarily arose from experiments in architectural design and were eventually transferred to fulfill the needs of preservation interests.
At the National Trust symposium in 1977, several of Michael Graves' architectural projects are illustrated to demonstrate the evolution of his approach to the historic context. The first addition discussed is the Benacerraf House, completed in 1969. The addition does not rely upon any kind of "cosmetic continuity" to connect itself to the existing building. Instead, Graves uses the addition to create a link between the house and a larger environment, nature, as expressed through a relation to the rear garden. The addition extends the interior space of the house into the rear garden, blurring the boundary between outside and inside. The volume of the existing house is maintained while the addition acts as a newly opened fragment leading into the natural world, a contrast to the dominant and enclosed attitude of the original house to the outside. The addition provides a new dependency between architecture and nature which had not existed before. A new reciprocity of architecture and nature, old and new, is created.(47)
Illustration 11 - Benacerraff House, Michael Graves, Princeton, 1969.
Despite Graves' explanation of the addition as a response to a larger environment, a landscape beyond the house itself, the addition was severely criticized as "so compulsive in its ‘modernity' that it deprives the original house of all meaning."(82) Graves and Wolf admitted that the relationship of the addition may have been overly abstract but they believe the general relationship between old and new is simply the reciprocity between any new structure and its existing surroundings, whether that environment is built or natural. Additionally, Graves and Wolf view the essential nature of architecture as a cultural artifact for human activity. Specific parts and elements of a building have particular associations with certain activities or meanings. For example, a window has a distinct familiarity to its users through its use, how one looks through it to something beyond or even its distinction from a door opening. Cumulatively, the distinction of these various parts and elements of a building assume symbolic or ritualistic roles beyond mere functionality. Graves and Wolf suggest the use of these symbolic architectural elements, present throughout the built and natural landscape, to establish a link between buildings of the past and present.(83) Graves and Wolf's discussion of symbolic architectural elements is possibly the first use such terminology in the context of preservation.
The use of these symbolic architectural elements becomes more clear in the later examples presented of Graves' architectural work. Immediately following the discussion of symbolic architectural elements is the second architectural example, the Gunwyn Ventures project, completed in 1972. The new work for the project is located completely within the shell of an existing Dutch Renaissance-style bank. The interior developed independent of the old building. In this instance, it is the exterior of the building containing the symbolic elements referred to earlier: windows, doors, entrances, and the like. It is through these symbolic elements that a connection is made to the greater landscape, filled with similar symbolic elements, while Graves' own architectural interests, the exploration of spatial and metaphorical readings, are pursued within the shell of the existing building. The symbolic elements are a wrapper around Graves' individual architectural explorations.
Illustration 12,13 - Gunwyn Ventures, Michael Graves, Princeton, 1972.
A later building presented is the Claghorn House, completed in 1974. Here, the symbolic architectural elements employed upon Graves' work are no longer authentic historical fragments like the shell of the bank in the Gunwyn Venture project but new elements designed by Graves intended to recall specific symbolic architectural elements and their specific associations. However, this method of design is not inherently different from the mode used in the earlier Benacerraf House but has only been slightly modified. As stated by Graves and Wolf:
The concern earlier was with proportion, geometry and metaphor, but the later work turns to more associative values of familiar artifacts and elements while maintaining the structure of the earlier approach. The more abstract attitude was modified by attention to the symbolic elements of architecture.(84)
Illustration 14 - Claghorn House, Michael Graves, Princeton, 1974.
Architectural similarities can be seen clearly in the Benacerraf and Claghorn Houses. Both are extensions of the existing enclosed house into the open space of the yard, arranged with in L-shaped plan. Sensitively placed planes and beams are used to define space and actually penetrate into the existing volume of the house encouraging a direct and immediate dialog between the two. Beyond these shared attributes, a new layer of meaning has been placed upon the Claghorn House. The dark base refers to the base of the Victorian house. The inset pediment represents the human occupation of the addition. The lattice on the side of the addition has a twofold effect. At a simplistic level, it provides an immediate physical and historical reference to the lattices common on other porches in the area but more important is the symbolic association of the latticework. The element is typically used as an enclosure on gazebos and porches, creating a semi-transparent effect. The many openings of the lattice allow it to dematerialize and allow vision through its surface, typically to a natural landscape beyond. Placed upon a solid surface, the symbolic associations with the lattice implies a dematerialized surface with a vista beyond. Graves and Wolf equate the effect to the highly polished marble surfaces designed by Mies van der Rohe which perceptually dematerialized the wall surface.(85)
The use of the lattice has significant ramifications in the theory of building additions. First, it creates a direct historical and functional reference to similar elements of other structures in the area creating a continuity of aesthetic. A stylistic unity has been attained. Second, by the lattice's association as a dematerializing element, it allows the mass and solidity of the new addition to seemingly disappear. This mass was an unavoidable programmatic requirement of the addition. With the application of a historical architectural element and its symbolic associations, the mass of the building disappears and no longer imposes itself upon the established historic context. With its disappearance, the historic context is allowed to remain autonomous and distinct, unaffected by any new addition.
Illustration 15 - The Mediating Wall
Michael Graves' lattice provides the basis for a metaphor which can explain a methodology of designing additions to historic structures developing from the need to balance the theories of stylistic unity and disjunction. The metaphor is the mediating wall. Through it, both integration and separation can be achieved. The mediating wall is located at a position where it can mediate the differences between adjacent old and new as experienced by the observer. Containing the symbolic elements of architecture, the mediating wall suggests a level of continuity with the surrounding context, whether the individual building or entire neighborhood. But beyond the wall, virtually any architectural mode can take place since it is adequately shielded. Also speaking at the "Old & New: Design Relationship" symposium, Paul Goldberger indirectly advocated the use of the mediating wall:
I do not mind the idea. . . of new programs hiding behind old facades. To say that the facade must reflect what is behind it is to be caught once again in the old modernist trap. That notion also denies the different demands of an internal building on the one hand and an urban context on the other.(86)The earliest basis for the mediating wall as it is applied to preservation issues can be found in the writings of Robert Venturi. Published in 1966, exactly contemporary with the National Historic Preservation Act, Complexity and Contradiction makes a call for a multiplicity of meanings in architecture and the built environment. Venturi rejects the simplification of architectural programs and forms which have directed the interests of Modern architecture since the early twentieth century. Venturi pleads for the creation of an architecture which is "both-and" as opposed to "either-or," an architecture encompassing the many variables influencing the creation of buildings opposed to the simplification of the built environment which elevates the importance of certain aspects while ignoring others at its convenience. For the mediating wall, the "both-and" definition is met by being a piece of the new, in terms of the construction time period, while containing the symbols of the old, a symbolic link to the past. It is a true expression of the complexity and contradiction of the Janus head.
A few years after Complexity and Contradiction, Venturi puts forth the architectural metaphor of the duck and the decorated shed. The duck is a building type expressing its form as an immediate response to the functions house within. However, Venturi favors the decorated shed, a method where a simple, even boring building literally has a sign placed in front of it telling the observer what purposes or functions of the building encompasses. These messages are conveyed through the application of culturally manifested symbols or even written words. Any symbol is appropriate whether formal or kitsch as long as the message conveyed in understandable to its audience. As demonstrated in Complexity and Contradiction, this application of symbols to the building form has been a long tradition throughout architectural history, a tradition which was only recently lost in the architecture of the modern era. For Venturi, the application of symbols provides architectural content.(87)
Illustration 16 - Football Hall of Fame, Robert Venturi
One of Venturi's early projects using the decorated shed most obviously is the competition entry for the Football Hall of Fame. A large electronic screen reminiscent of a drive-in movie theater dominates the intended entry to the building. Sports images and other memorabilia are displayed upon this screen. The actual museum space is position behind this screen. It is a simple vaulted space considered a black box by a museum curator or shed by Venturi. The vaulted space creates flexible open area for displays or exhibit arrangements and the possible projection of more sports images on the ceiling and walls of the interior. At a more recent project, the Children's Museum of Houston, Venturi uses a similar architectural method. In this case, the building creating the actual museum volume is possibly the most banal building type available, the Butler Building. This building type is the trade name for a pre-fabricated metal shed available in various lengths and widths that can be easily, quickly and cheaply erected to order on virtually any site. On the primary street facade and corner of the building, stucco pilasters, columns and a pediment are applied to give the building symbolic meaning and a link to a greater architectural tradition. A side walkway is supported by fiberglass "caryakids," multi-colored, larger-than-life cutouts of children acting as symbols representing the building as a place for the young.
Illustration 17 - Children's Museum, Robert Venturi, Houston, 1993.
At the heart of both schemes lies a simple, virtually meaningless and banal building. It is this building, devoid of any symbols, creating the actual volume and enclosed space to accommodate programmatic needs and intended functions. But if Venturi's Complexity and Contradiction is read closely, it is possible that the buildings receiving these applied symbols could be either a simple shed, as he suggests, or a building conceived in the Modernist aesthetic. Venturi views the Modernist building as complete banality; its simplification of aesthetics to puristic levels and reduction of programmatic and functional requirements to a basic parti can not result in an architecture of complexity. Quite simply, the Modernist building is devoid of all symbols.(88) Both the Butler Building and the Modern building are seen as banal and effectively expressionless.
For the preservation movement, Venturi's definition of the meaningless and symbolically depleted building stands in complete contrast to the pre-Modernist historic structure which has attained value not only due to its age, but also due to the various symbols which have been placed into and upon it. These symbols are readily understood due to their relation to an architectural and cultural tradition or, as Graves and Wolf have described, the symbolic elements of architecture. The shed can not compete with the historic building in regard to its symbolic expression and it will remain subservient to and detached from the historic artifact as long as the overall scale, size, and location of the new building does not overpower the historic structure or its context. Through this definition, the theory of disjunction is fulfilled. By employing a perceived banal aesthetic for any additions, the historic structure can remain in historic and aesthetic isolation from any new construction. Actually, virtually any architectural design methodology can be used, as long as its symbolic readings do not immediately conflict with the historic artifact or context. The old is immediately recognized as the higher in status and value.
This new construction, despite its apparent and desired lack of competitive symbolic meaning, must give some type of reference to the historic context so that the surrounding environment is not overly damaged, hindering the theory of stylistic unity. Thus, architectural symbols are derived from the historic building or its context and placed upon the new; the mediating wall has been created. The historic building's higher regard is maintained because it acts as a primary aesthetic reference. Additions defer to the prototype and remain secondary in the aesthetic hierarchy.
Venturi provides a prime source for the establishment of the mediating wall, especially since his work appeared at the same moment the preservation movement gained strength in the 1960s, but the characteristics of the mediating wall can be traced from other sources. The treatment of the wall as an individual design element has not been solely pursued in the relationship between old and new architecture in the past twenty-five years.
Though the mediating wall is not necessarily a detached element, the argument for its symbolic distinction from the remaining expression of the building can be paralleled to the research of Kenneth Moffett. As an architectural element, Moffett argues that the wall has slowly gained a sense of autonomy in design both in two and three dimensions. As a two-dimensional, flat surface, the wall is often treated with the exuberant, painterly and sometimes undisciplined use of ornamentation upon the wall itself. A motive at work may be "...a wish to reduce scale and increase interest in situations in which functional demands alone could present a dull and featureless facade..."(89) This feature parallels the mediating wall's desire shield the new addition from view and match the scale, color, material, and character of the surrounding context.
As a more recent trend, the wall acts as a independent element completely, freeing itself from the attached volume to attain full autonomy. Citing the Meyerson Symphony center, designed by I.M. Pei, the L-shaped armature of the building acts as a reference against the freely varying volumes of the building the wall partially embraces. The positioning of the wall is a contextual gesture to the street grid of Dallas and can be read as an overscaled colonnade barely visible in the greater composition.(90) Although extremely abstracted, these contextual gestures combined with the armature's role in collecting the masses of the composition provide an example of the mediating wall.
Illustration 18 - Meyerson Symphony Center, I.M. Pei, Dallas, 1989
The mediating wall is also fostered by the nature of preservation practice and the legal tools used to protect landmarked buildings. Quite often, only the exterior portions of a building are regulated by law or, more specifically, those portions of the building which can be viewed from the public right-of-way. As determined in various legal precedents, the government's role is not merely to protect the public from poor living conditions but to enhance the living environment for the citizens of the community.(91) These enhancements include historic preservation activities. However, this control generally does not extend into the interior of the building, the private realm, since regulations of the interior limit the owner's potential use of the building. For this reason, many local municipalities do not recognize interiors as contributors to the historic environment. Thus, the historic structure becomes a mere shell for the activities held within its exterior walls. It is an interior volume which can be manipulated as desired, just as the architectural treatment behind the mediating wall can use any possible means.