His primitive hut is eminently transparent, but is this indeed the origin of architecture?
Without a doubt transparency would appear to be fundamental to any definition of SPACE.
The condition of opacity is the condition of the object, solid and weighty, bounded by the laws of physics and chemistry.

The condition of transparency is that of light and air, a free space of imminence, where people and animals move between fixed objects, where storms develop and sunlight moves. It is where accidents happen; it is the stage of our life, and as such it is fundamental to our conception of space, and therefore also of architecture.

But this essential, positivist understanding of Transparency is, of course, quite literal, and if you will bear with us for a moment we would like to go a little further into the question posed by such a title.

In architecture, there are also ways of understanding transparency that are not so literal. The first we might call a figural transparency, a consideration more related to the complexities embodied in a developed work of architecture, complexities that have more to do with the characterization of a space in the mind’s eye; where the various experiences of viewing a work of architecture, passing though its doorways and climbing its stairs, studying, perchance, its façade, are put together in our imagination; where the overlap of these elements, their congruencies and mismatches necessarily merge; and where an idea of the building’s fundamental nature and form is synthesized.

Our very means of working relies precisely on this more obtuse form of transparency, where elements that do not always have an immediate spatial connection are overlaid and temporarily seen together (and, it should be noted, sometimes confusingly fused). Building up our designs in a series of layers, we employ the transparency of our working media to coordinate different parts of a building and synthesize the whole. In our particular case, because of our age and our inclination, our transparent medium of choice is tracing paper. In an old-fashioned way we lay plan over plan, elevation over section, and thereby develop a spatial structure that suffuses the whole project, but the same principles apply equally to the wire-frame models of architects working directly in 3D computer models.

The working methods of architects therefore make up a kit of magic tools, instruments that allow their eyes to be for a brief moment all-seeing, and thanks to the magic quality of these tools, the transparency of their media, and to the architect’s own ability to hold in their imagination forms that will not ever be seen or experienced simultaneously in the built work, they are able to create works of complexity and interest. The test comes when the public enters the finished construction.
Are the formal structures apparent? Are the motifs and patterns experienced? Is there coherence to the sense of the whole? Does the visitor come away with a sense of what the building is, or how it is? Generally, we think of non-architects as absorbing the experience of buildings subconsciously, following the cues put before them by the architects and, we hope, enjoying the buildings in the way it was meant to be enjoyed, or at least as we saw them in our imaginations.
 
Perhaps the most pivotal work on the nature of transparency in architecture as we are discussing it was the 1956 essay “Transparency: Literal and Phenomenal” by Colin Rowe and Robert Slutsky. Taking their cue from Gestalt Theory and the writings of Gyorgy Kepes, founder of the Center for Advanced Visual Studies at MIT, Rowe and Slutsky describe both of these types of transparency as they relate to our field of practice. This essay, as most of you probably know is in both its first and second parts,  a valuable read for any architect.

Beginning with an analysis of cubist paintings, Rowe and Slutsky swiftly move on to a comparison of iconic structures of the Modern Movement in Architecture, and later of some examples from the Italian Renaissance. What interests these authors are works where there emerges an overlap of different readings, especially those where the simultaneous recognition of contradictory readings generates a vibration, and where this vibration, this oscillation between different readings in turn creates additional readings. These are experiences that, according to Gestalt theory, are available to everyone, not just architects or students of architecture.
But having for a moment these figural forms of transparency, we might also return to an appreciation of the literal kind.

When we first founded Moneo Brock Studio we had a number of projects whose relative small scale or budget (or both) allowed (or forced) us to concentrate on the material aspects of architecture, exploring the modulation of space through the exploitation of textures, colors, and light. Because of our early experience designing lofts in NY, where natural light was in many cases a scarce resource, we have always been drawn to transparent, translucent and iridescent materials, used in these first projects to refract and reflect natural light from windows at the façade deep into the space of the loft.

We discovered in the process that these materials have a chameleonic aspect in their behavior, especially in their response to changing qualities of light. Working in these reduced spaces and with the propagation of natural light a priority, searching for solutions to the issues of limited space and natural light, we discovered an Architecture of materials, colors and textures. By means of the use of screens to control light penetration we found that we could also generate colors and patterns as the contrast between light and shadow evolved with the movement of the sun and the potency of the sky.

The glass block also belongs to this category of tectonic and chameleonic. As a solid building material it exhibits great strength and solidity, and yet its responses to light are marvelously varied. The coexistence in a single material of these apparently contradictory qualities interests us and draws us to the material.

In the Panticosa Baths project, glass blocks were employed to bring light to the building interiors, which faced the mountain on all sides. Using different combinations of translucent wall, vision glass, and screen walls made of columns of glass blocks, we were able to modulate views of the surrounding landscape and provide just the right amount of light and orienting cues for the visitors inside.

But this project exemplifies our understanding of phenomenal transparency. At Panticosa the spatial arrangements are very complex, and the partitioning of the plans somewhat labyrinthine with repetitive and circular patterns of circulation, twists and turns of walls and a multiplicity of interconnected levels, and yet the consistency of the design language and the possibility of making repeated reference to the different mountains peaks both serve as orienting anchors, giving visitors a sense of where they are in the building at all times, and giving them a sense of its organization.

We planned the program distribution in the building volume with an eye towards the exposures, and to the sequences defined by the building’s location and our understanding of the possible liturgies of a visit to the baths, and we developed a strategy for the exterior massing in view of this volumetric arrangement, coupled with our intention to modulate light to the interior and views to the exterior.

When giving form to our conceptual model we realized that there was a phenomenal transparency at work in our hands. We had simply decided to build the model with no floor slabs, as this gave us the ability to appreciate all the levels simultaneously. As we built this model we were forming a multitude of spaces as if they were one, and in so doing gave them a coherence that transcended any possible simultaneous experience. This simple model served as a great tool for our own understanding of the nature of the building, and as a constant reference as we developed the plans in more detail.

At Columbia University, where we helped Rafael Moneo develop his design for a new Sciences Building, the operative concept of Transparency is at first philosophical, relating to the design process as it incorporates a series of structural solutions. Later, as the façade design redraws the building structure (without revealing it literally), the question moves to a kind of virtual transparency, where the structure is seen but not seen.

Curiously, the site for The Northwest Sciences Building was not entirely free, being that the campus gymnasium occupied 2/3 of the ground area over which the new building was to sit, and the gymnasium was not to be removed but rather preserved (and furthermore maintained in use during the construction of the new building). The new building, including research laboratories for chemistry, biology and physics, required very stiff floors in areas of the plan lying directly over the gymnasium, which could not be perforated with columns. The requirements for the building structure were therefore formidable, and the structural concepts became all-important as the magnitude of the engineering work became evident. The structure, we saw, would necessarily leave its imprint on the building’s architecture.

The negotiation between the building’s architecture and its structure thereafter became the heart of the building’s concept, structure and architecture becoming intimately fused in a solution that proved not just the most efficient use of steel but also a highly gratifying frame design. Using the concept of a braced frame, the entire façade envelope was put to work spanning the 120 feet (40 meters) over the gymnasium and, by means of a computer analysis studying the reactions to typical loading conditions, the braces were optimized for orientation and position. The result was a frame whose very image betrays the highly specific requirements of the building structure, showing the flow of stresses as they pass across the façade, the energy of the steel drawn across the facade.

This transparency of function is not atypical in buildings whose structural elements play such an important role, but what followed in the façade design was of even greater interest.

The revelation of the hidden structure was achieved by means of a “negative” drawing, where the field surrounding the frame elements was given a strong relief, a deep texture of extruded aluminum fins running parallel to the structural frame, but not over it. In this way the structural frame is redrawn on the facade by the periodic absence of fins; the frame, which is not there on the façade but hidden behind, absent, is nonetheless there represented by another absence: the break in the pattern of the fins.

In the Columbia building façade design we find not just a virtual transparency, where the frame which cannot be seen is seen, but also a transparency of means, where the expression of structure cannot be frank (a la Beaubourg) but can only be alluded to, where the clarity of the structural system is emphasized through the idealization of the frame geometry, and its subtle beauty made accessible through the paring away of detail.

In the project for the Glass pavilion at Cuenca, we find a different problem at work entirely. Where the Columbia project exhibits philosophical, virtual, and methodological Transparency, in Cuenca we find a phantom Opacity lurking in the refractions of the crystalline pavilion. It could be that the source of this trouble can be found in the program brief, asking for a covered plaza in the middle of an abandoned flood plain. In any case, the design process took us on a search for an anti-module module, where errant compositional urges pushed us to defy the centralized and/or the linear combinations that typicaly spring from the application of repetition in modular constructions, as we searched for a more fragmented, looser assembly. The module is buried deep in the thicket of steel, inaccessible to the viewer on the ground, from inside or out. Only in the orthographic drawings is any sense of the structural order readable; in real space there is only the continuum of shards of glass and steel. Ironically, the very transparency of the structure works against its understanding, contributing to the opacity of the design.

Belén Moneo and Jeff Brock