Elements of Architecture: The Wall

The wall is one of the most primitive and enduring elements of architecture. In ancient times, the wall was used as a fence, barrier, definer of property limits, an outer covering for buildings, a support for the roof, a separator of internal spaces, and a thermal and moisture insulator, as well as a space for accommodating household furniture and tools. Today, these functions have been separated, and for each one a distinct element has been devised. These elements are sometimes used in combination and sometimes independently within a building.

From a spatial perspective, the wall plays an important role and in most cases defines the boundaries of space. Beyond its instrumental role in relation to space, the wall as an independent element and a kind of “presence” holds a special significance. Architecture over the centuries has been a language whose vocabulary consisted of architectural elements: doors, windows, stairs, walls, and so on. The “grammar” of this language—the rules for combining these elements—has been the syntax of architecture. These rules have originated from a kind of wisdom and logic, and at the hands of architects they have acquired aesthetic value. For example, the rule of placing windows beneath one another, so that they form limited rows on the facade, derives from the fact that in load-bearing walls a window is considered a weak point and no significant vertical load can be placed on the span where an opening is located. Forces are inevitably transferred to the piers around the window. It is for this reason that stacking windows has emerged from structural logic as an aesthetic norm.

Today, the needs that have historically shaped the wall as a familiar element have changed due to advances in technology. The question that remains is whether the wall should be retained in its recognized form or replaced by a new element. If architectural elements disappear from the scene of architecture, the language referred to above also vanishes, for language has no meaning without vocabulary. What remains is sound. On the other hand, we know that a significant part of modern art replaced figurative representation with abstraction, and modern architecture similarly replaced visual meaning—which in the process of cognition precedes the emergence of meaning—with it. Modern architecture, though initially claiming a Cubist and abstract aesthetic, could not achieve the purity of painting due to its dependence on the technology of the time, and continued to retain doors, windows, columns, and walls. Today, technology has given architects the ability to command form and materials to the same degree as graphic designs and paintings. Walls can have whatever materiality, transparency, color, and texture the designer wishes. The presence of a window is no longer necessary—the wall transmits light and views to any desired degree. It is for this reason that today, instead of the word “wall” (exterior), the term “skin” is used—a skin that can define the form of the architectural vessel. New technology has made it possible for the degree of rigidity, transparency, or texture of the skin to change gradually, and in this way wall, roof, structure, and window can merge into one another.

The process of unification—a hallmark of industrial design and avant-garde architecture at the end of the nineties and the beginning of the third millennium—seeks to consign the wall, after at least ten thousand years of permanent presence on the scene of architecture, to the hands of history. Just as industrial products are now made of fewer but more complex components, architectural products too—roof, floor, wall, stair, ramp, window—and, as Peter Eisenman puts it, the “recognized elements of architecture”—are being set aside to create a new, unexperienced phenomenon that cannot be decomposed into separate, independent parts. Industrial assembly, the equivalent of montage in painting and composition in architecture, strives to crystallize all elements in a single, continuous object.

Therefore, a new aesthetic for organizing such phenomena in the realm of form and space is needed. The family of soft and continuous forms, arising from the world of natural and complex forms, derives not from the “method of connection” and variety of elements but from the internal movements of continuous and unified forms.

Pioneering architects, in pursuit of this aesthetic, have approached the wall in architecture from various angles. In some instances the wall has become invisible, and elsewhere it has been transformed into a sophisticated device that communicates with people; it reacts to environmental conditions; it changes color throughout the day; with a weak electric current and controlled conductivity it becomes transparent or opaque; and at human command it displays various images received from computers, satellites, television, closed-circuit cameras, video phones, slide projectors, and video players.

Some, using special effects such as laser, mist, artificial fog, and other means, have created astonishing virtual walls. Another group has pursued new materials for walls: walls made of glass with glass support structures; walls constructed from various types of thin and ultra-light panels (PVC) whose weight in some cases reaches approximately one kilogram per square meter; walls composed of mineral or natural fibers or made from composite materials—resin, artificial stone, gum, concrete, and more. On another front stand the advocates of the environment, who invent in various forms walls that absorb and utilize energy, or green walls composed of natural materials and living plants.

In the 1960s and 1970s, a number of architects following the social and political movements of the time built walls from empty soda cans, bottles, tins, and similar objects—as a distinctive protest. Today, the use of recycled materials—not for socio-political reasons but as an experiment in alternative methods and in support of sustainable development—has been explored in some experimental works.

Meanwhile, a group of artist-architects has sought to valorize the wall as a prominent and important element of architecture in entirely new ways. Herzog and de Meuron are among those who have carried out extremely important experiments concerning the pattern, texture, and transparency of walls. In this pursuit they have sometimes employed the most advanced technologies, such as printing on glass, and sometimes the most primitive techniques, such as dry-stacked, hollow, and graduated stone construction.

Mario Botta has transformed the wall into an architectural monument. The corporeality of the wall, the dark and light stone blocks laid together with scientific precision and masterful craftsmanship, the geometric patterns sometimes inspired by the Romanesque architecture of southern Switzerland—all emphasize the wall as a prominent element of architecture.

The architects known as High Tech, with greater delicacy than in previous decades but still grounded in their own principles, build transparent, lightweight, and “intelligent” walls by assembling standard and highly sensitive components. Their experiments are sometimes tedious and sometimes magnificent.

Some believe that building decorative brick walls is a work akin to carpet-weaving—pieces, like carpet knots, are placed together to create a particular pattern. Today, among a new generation of architects, some are inspired by traditional methods and motifs in pursuit of this experience. Among the prominent modern architects of the older generation, Alvar Aalto was the only one who carried out this work in a new and remarkably beautiful manner.

The modern thinking of “architecture and honesty,” which the New Brutalists and architects such as Stirling and the Smithsons employed in building walls of brick and raw, rough concrete, still has many adherents. Tadao Ando generally builds walls of exposed concrete and glass. The concrete wall has become part of his ideology.

Traditional materials and technologies, or those rooted in tradition, also still prevail. Paper walls; walls made of fired clay pioneered by Nader Khalili; cob walls; walls made of reed, unbaked brick, and similar materials—all of these are inexpensive and extremely durable, and if not destroyed by human hands, would have remained standing like the magnificent walls of the Arg-e Bam. In Europe, many prehistoric houses and in Iran from distant pasts until before the modern era, houses were built with tall walls and small openings to the outside. Beyond regional, cultural, and social roots, this arrangement also served a defensive purpose.

A. Defense

Many ancient cities and settlements were walled for defense. In Iran, city walls were mainly made of mud brick and unbaked brick. These are inexpensive and extremely durable materials, and if not destroyed by human hands, they would have remained standing like the magnificent walls of the Arg-e Bam. In Europe, many Neolithic villages had walls made of stakes driven vertically into the ground. In antiquity, many defensive walls were built using large blocks of stone. With the invention of the cannon in the fifteenth century, builders discovered that stone walls, though extremely resistant, could not withstand the impact and shockwaves of cannon fire and would shatter. Brick walls, though of lesser resistance, absorb the shock of an explosion. For this reason, brick and reinforced earthworks were employed in building fortifications for castles and cities, along with stone walls.

Iranians, when building garden walls with brick, would sometimes construct the top few rows using brick courses with very little mortar, so that intruders attempting to enter the property would, while climbing the wall, bring a number of bricks crashing down upon their own heads.

B. Property

The wall is the boundary of property, and the boundary of property is one of the most enduring characteristics of historic cities. The ancient urban fabric of historic cities such as Yazd, Damascus, and Turin (in Italy) has been rebuilt many times, yet its elements—due to the persistence of private and public property boundaries—are still legible and intact. In ancient Europe, due to the abundance of timber, wood was used for constructing buildings. After several great fires in ancient cities, such as Rome, local authorities realized that when a wooden building was destroyed, the property boundary also vanished. For this reason, they decreed that houses should be built at least to a certain height in stone or brick, so that “its footprint would remain.”

C. Structure

The wall is the oldest vertical structure, and its primary role in the past was bearing the weight of the roof and the floors of the building. The system of load-bearing walls and the limitations of spanning them with horizontal beams, arches, or domes has given shape to architectural typology. The structure of the Mesopotamian palaces of the first millennium BC, lacking columns, was composed of thick, closely spaced walls; hence the numerous halls with relatively narrow widths and considerable lengths. In ancient Rome, load-bearing walls were built with a shell of cut stone and a concrete core. For making this primitive concrete, volcanic ash was used in place of cement. The Romans were empirically acquainted with the resistance of materials and the internal forces in buildings. In the construction of the Pantheon, seven types of stone with varying degrees of hardness and weight were used—granite at the base of the walls and lightweight, porous volcanic stone at the highest part of the dome. In the Western world, the Romans were the first to employ so-called “finished” walls—buildings that in appearance followed the Greek style but in practice, instead of walls built with solid stone blocks, used concrete and brick walls faced with carved stone slabs. The Achaemenids also used unbaked-brick walls covered with stone in many instances. In Sasanian and Islamic architecture, load-bearing reinforcement piers—with the function of lightening the load-bearing wall both physically and aesthetically—were employed. Today, load-bearing walls in specialized structures are mainly of reinforced concrete.

D. Space and Aesthetics

For years upon years, the wall has been the most important agent of form-giving in architectural space. The growing complexity of architectural space, following the increasing complexity of functional relationships, was achieved through the division of interior space by means of walls. The primitive villages of the Neolithic period were composed of single-cell units, each dedicated to a single function: sleeping quarters for the woman, sleeping quarters for the man, grain storage, the stable for the husband’s cattle or sheep, the stable for the eldest son’s cattle or sheep, and so on. Gradually, two-cell, four-cell, and increasingly complex buildings came into being, and walls gave functional form to space. In certain types of architecture, space was organized in a special way by walls for aesthetic, symbolic, and religious reasons. The ancient Mesopotamians, like the Romans, first drew the footprint of walls to design architectural space, and thus invented the “plan.”

At the beginning of the nineteenth century, Boulton and Watt built a spinning factory in Manchester in which, for the first time, cast-iron columns replaced load-bearing walls. The new spinning machines required a vast, continuous space, and the presence of thick load-bearing walls and piers prevented this. Cast-iron columns opened up the interior space, and the emergence of independent metal and concrete frames paved the way for Le Corbusier’s free plan. In Villa Savoye, Le Corbusier placed the entire weight of the building on pilotis, and the walls serve only to give form to space.

In the Chapel of Ronchamp, Le Corbusier departed considerably from this idea. The wall of this chapel is, as he himself jokingly said, “foolishly thick,” so that its deep openings—decorated with colored patterned glass—evoke the spatial quality of Romanesque churches. In this project, the wall has become one of the most essential components of the building.

E. Thermal and Acoustic Insulation

The thick walls of the past were at the same time excellent insulators against heat, cold, and noise. Today, due to space limitations and the high value of land, these same properties are provided through the use of special chemical materials. In the 1950s, double-skin walls became widely popular, but today it is generally preferred to use fiberglass sheets, polyurethane, or other synthetic materials as supplements to thin walls.

In any case, if we reflect on the past of architecture and the social role of the wall, we realize that it is one of the most important and fundamental elements of architecture, which over the course of history has become one of the innate expressions of human life. The concept of “four walls”—a symbol of home, shelter, the domain of family and private life—exists in some form in all cultures. Historic walls like Hadrian’s Wall (the Roman emperor) and the Great Wall of China have passed into legend, and the Berlin Wall—whose erection and demolition mark the beginning of two important periods of modern political history—is part of human culture.

Today we know that the wall as a recognized element is in the process of disappearing. Yet it is more important than individual tastes, and for this reason one cannot easily do battle against it. The question is: Is it possible that the numerous experiments conducted on skins or new architectural separators might one day be synthesized and offered as fundamental solutions to users, or will they forever remain mere “experiments” and inventions? In reality, by setting aside a ten-thousand-year-old element, we are also setting aside its accumulated experience and knowledge. A few months or even a few years of creativity cannot provide sufficient assurance that a work is satisfactory in all aspects—technical, social, psychological, and hygienic.

For example, the modern architectural experiments of the 1920s are often far weaker in terms of maintenance and durability than traditional buildings. It seems that adding to the culture of architecture through the invention of new things and concepts has taken priority, while responding to human needs has been placed second. When the architect attains the status of scientist, artist, and philosopher, the process of invention and creativity becomes inevitable; yet it seems that in today’s consumer world, the variety of production and invention far exceeds what is needed and is vastly beyond humanity’s capacity to control the tools produced and to digest them culturally and psychologically.