Here, Project Director Alistair Brierley explores the concept of the wall and how the primary structural element has developed over time to possess deep complexity in terms of structure, role, and metaphorical significance.

In isolation and solitary, a wall may have particular resonance and symbolism in terms of its functionality and purpose, its form and scale, and its materiality. Mythologies and reputation have imbued certain walls with an importance and significance that travels far beyond their construction. The demolished Berlin Wall, the Great Wall of China, or Hadrian’s Wall are all cultural icons of global significance, and represent multi-layered and deep resonance across social, cultural and political borders. By and large the messaging and connotations surrounding the ‘wall’ in this context may be construed as negative. These walls were primarily defensive, divisive, impermeable and physical barriers to human movement. By their nature they have divided societies, blocked communication and created ‘them and us’ scenarios. A wall cannot justify its construction and maintenance without a gradient of some sort, be it economic, political or territorial. The morphology of such walls tend to be linear, extruded and stretched across and through landscapes, towns and cities.

Within the defensive paradigm, the linear wall can curve, bend and fold to create sealed enclosures. This means that rather than a binary separation of two adjacent components or land parcels, the sealed and enclosed entity is performing the same defensive or protective role as its linear counterpart, but in an entirely different way. Whether Carcassonne, Dubrovnik, York or Toledo the walls were built to provide security and safety in uncertain times.

Besides keeping those within its curtilage safe, a wall also holds, retains and incarcerates those within. A prison is designed to be impervious to escape, just as the wall of a dam must contain and hold its huge volumes of retained water. The dam describes the notion of the wall as a separator particularly well. Without the need for some sort of gradient, (be it physical, political, financial or sociological) a wall would not be necessary as there would be no imperative for its construction. This notion of the wall as a divider and marker of different environments can be extrapolated and interpreted in a variety of settings. For the architect, whether designing a retaining wall, or a non-load bearing panelised system supported on a frame, the principles of protection and modification and control of two different environments are similar.

The architectural personality and character of walls are multifold and have been developed to solve and address various performance criteria and requirements throughout centuries. Before the development of frame buildings the wall needed to be loadbearing in its entirety. Often the profile would have been battened to widen at the base to provide the requisite stability, and foundations would have been aligned to pick up the continuum of weight transferred through the masonry construction into the ground. An awareness of Newtonian physics, and the inherent forces applied to any structure means that in engineering terms the wall is actually a vertical cantilever subject to the normal rules of physics. Slenderness ratio (height to width), modularity (brick, stone, rubble or mud) all come into play here, as well as the length of particular sections of a wall. Whether a wall is straight or curved in plan, form will also have a bearing on its structural stability and whether it is built on a slope or on a flat surface. Ground conditions and foundations are also integral to the design of a wall, and whether deep or shallow subterranean support and stability is easily available.

Historically it is interesting to note that Vitruvius, Alberti and Andrea Palladio were more than aware of the practicalities of building, as well as the more academic discipline of proportion, and the use of particular columns and their associated capitals for specific temples and civic structures. Palladio after all came into architecture via the route of expert stonemasonry, and knew how to optimise materials in specific contexts within the Venetian plain. Within the classical genre of Palladio’s work, the wall is often enhanced and provided with additional articulation with the introduction of pilasters, and half and full columns actually separated from the wall itself. 

Perhaps most important of all is the use of openings with the surface of the wall itself. Without a wall there can be no openings, and as such these two variables are inextricably conjoined. On the basis that the use of walls in early civilisations were primarily defensive, the use of the void or cut out space was used sparingly. Gateways providing access to fortifications were minimised, and were strengthened with turrets and walkways directly behind the battlements. These were points of vulnerability and had to perform a specific role.

The temples of the ancient world also used very few openings in wall surfaces, largely because the function of the temple, and the worship of particular gods was an introverted and intense experience. An entrance into the chamber was likely to be the only opening within the rectangular container. The single entrance would however have been celebrated and decorated with an applied system of pilasters, lintels and pediments, and the actual surfaces of the walls smooth and clean cut from huge blocks of precisely cut stone. This threshold would have been seen as a portal or threshold from the outside world into that of Venus or Zeus, and was loaded with symbolism. The symmetry of the positioning of this entrance also added to its importance and significance.

A more contemporary and infamous wall divided Berlin from 1961 until its fall in 1989. It was built to prevent East Germans from fleeing to the west, and stopping the economically disastrous migration of workers. Symbolically it was a potent representation of the Cold War, and ran for 96 miles (27 of those within Berlin. It was in fact two walls that rose between 3.5 and 4.8m high built of reinforced concrete.

I experienced this wall in 1980 whilst undertaking a trip with the Bartlett School of Architecture, and the intensity of the experience remains. As we approached Berlin, the full extent of this construction became apparent - particularly the multiple watchtowers and the death strip complete with tripwire activated machine gun posts and landmines. It was both ominous and sinister and left us all silent and uneasy. Once within the city of Berlin, we crossed from east to west through the legendary checkpoint Charlie on the Friedrichestrasse. It was here, whilst the guards checked our papers and swept our bus for magazines and western food and goods, that the notion of controlled and uncompromising separation became intense.

This is the most politically and symbolic threshold that I have ever passed through, and has helped me to understand the resonance and physical messaging that a wall can communicate. The growing tension as one approached the moment of crossing, followed by the experience of having transitioned through this point felt like a significant decompression, albeit paired with the awareness that we had gone over to the other side in terms of Cold War parlance. Our objective in the east had been to visit the Bauhaus in Dessau, the villas of Schinkel in Potsdam, and the Einstein Tower hidden in the forests close to the border. All of these experiences were enhanced and intensified through the knowledge that we had passed from one world to another, and the anxiety that perhaps we would not get back to the west.

There are other examples of walls or barriers that have been created over time, and the philosophical and ideological positioning remains the same. The wall primarily performs a containing, protective and separating role. This separation is implemented for a wide variety of reasons whether political, territorial, safety, comfort or protection. Protection from external factors, be they climatic or ideological.

When viewed through this lens, the wall becomes imbued with a mythological and symbolic language. The reputation from afar that a wall may engender is well known. The reasons for this are that containment and separation speak of mystery, secrecy and the unknown. The labyrinth in Knossos was formed of a complex arrangement of walls that created a maze of such sophistication that all who entered were at risk of being subsumed and absorbed by its sequential spaces and places. Thus here the configuration and arrangement of individual walls combine to build something mysterious and intangible. In a more contemporary example, the novel The Secret Garden by Frances Hodgson Burnett speaks of the veiled and separated world that exists within a space that is isolated, contained and separate. A key to a single door provides a way in, and subsequently the arrival of spring and the garden's restoration.

So far, this essay has looked back to antiquity as well as the more recent past. The constant theme here has been the solidity and impregnability of the wall. If we move forward in time the wall can be seen performing additional roles in terms of both its construction and symbolism. A wall ceases to be just a physical barrier when it transcends its traditional function and takes on a symbolic or metaphorical significance. In society a wall might no longer be just a partition, but rather a canvas for artistic expression, a conduit for storytelling, or conversely a statement of transparency and openness. When a wall becomes a metaphorical threshold, it may represent the breaking down of barriers between spaces, ideas and people. Walls encapsulate a sense of enclosure and protection defining spaces for introspection and refuge. Such walls may carry historical narratives, reflecting the passage of time, and the accompanying layers of human experience that have marked the wall.

A ‘wall’ based project that has always fascinated me is the Running Fence installation by the artist Christo and Jeanne-Claude. The project involved the construction of a fabric fence that extended for 24.5 miles across Sonoma and Marin counties in California. The purpose of the Running Fence (which was completed in 1976) was primarily artistic and environmental, with its strong interaction and engagement with the surrounding landscape. It followed the contours of the land, crossing hills, meadows and even traversing roads.

The sinuous and winding curves of the installation encouraged us to focus on the transient nature of art as reflected in the natural world. As a temporary structure, its impermanence added to its allure, emphasising the ephemerality of artistic expression, whilst challenging the notion of art and the wall specifically as a permanent fixture. Beyond its aesthetic and environmental considerations, the Running Fence project sparked dialogue about art, nature, and the relationship between human intervention and the landscape.

In complete contrast to the poetic and thoughtful Running Fence project, the wall envisaged and partially constructed by the Trump Administration in 2016 (to create a barrier along the south west border of the US) has been a source of controversy in terms of its symbolism, as well as the social and environmental damage that it has caused. The 8m high tightly spaced steel columns rooted in heavy concrete foundations do not run contiguously, and use already built sections of partially finished wall. Inevitably, besides the divisive and harsh presence of the actual physical barrier, the resonance of its presence encompasses harm to natural habitats and species, water management and sustainable agriculture, and the undermining of the economies of indigenous native populations and their sacred burial sites.

Perhaps more authentic and imbued with deeper sociological, cultural and economic significance than both the Trump and Christo and Jeanne-Claude projects are the dry stone walls constructed over centuries by farming communities in specific parts of England, in particular Derbyshire and Yorkshire. Seen in other societies across the world it’s clear that the building of such a wall requires a meticulous understanding of local geology, climate and the properties of individual stones. The craftsmanship becomes a form of cultural expression with distinct regional styles identifiable. The symbolism and resonance of the Neolithic tomb at Skara Brae in Orkney (blended and built into the earth) is evident and potent, and dates from 3200 BC. Such walls can be found in most parts of the world, and are a key example of how society used local materials and nothing else to improvise, and create systems of enclosure, defence and habitation. The lack of cement, and the skill of the construction involves careful selection of individual stones, and allows for the integration and acceptance of nature in the form of small mammals and reptiles, as well as birds and shrubs and grasses.

As well as the more vernacular and domestic scale of the farming enclosures seen in northern Europe, the dry stone wall reached its most sophisticated and elevated level at Machu Picchu in Peru where the Incas used this form of construction to complete complex and detailed habitable construction.

The consideration of the dry stone wall in society, the multiple roles it has played over millennia, its inherent simplicity and integrity, and its green credentials all bring it into focus as a significant and far reaching version of what we recognise as a wall. It’s clear and obvious functionality, its universal adoption across civilisations, and its ubiquitous flexibility all recommend it as a key component of human habitation, occupation, division, shelter and religion. Although not overtly symbolic and sophisticated in its everyday use, it has by stealth become part of our agricultural and ancient civic settlements. It also accepts its environmental and ecological responsibilities to those who encounter and use it. Openings can easily be cut within it, water can flow underneath, birds can nest, and its construction methodology requires nothing but the skill of making the right choices in terms of each and every stone. Everything is integrated, co-ordinated and set in the context of its prevailing landscape, and its specific position within the physical and symbolic places we inhabit.

"Any particular atmosphere or statement that a wall engenders comes from the human response to its suggested intention."

There can be no succinct or definitive moment of conclusion in the discussion around the wall and its symbolism in architecture. Any particular atmosphere or statement that a wall engenders comes from the human response to its suggested intention. It is difficult to argue against the wall being a neutral or entirely democratic response to its particular role in a specific place in society. We understand that the purely vernacular role of the wall, utilised in the domestic dwelling is to provide shelter and safety. These small scale architectural gestures are however loaded with intense symbolism for their occupants and wider society. By its very nature, the purpose of a wall is to be divisive. The reinforced concrete of the retaining wall of a dam, the protective wall around the medieval city, or the sheltered courtyard within a middle eastern home all create an immediate differential between two environments, and a means of controlling and ameliorating specific conditions, be they physical, philosophical, ideological or political.

The potential variations of the physical wall are almost infinite when one considers immediate context and given performance criteria. This is almost a contradiction for something that is so universal to our daily lives and experience, and only comes into a sharper focus when additional resonance and meaning is applied through the lens of history. Walls that are yet to be built may also carry symbolic weight, and the reasoning and grounds for envisaging such a wall will be grounds for intense debate.