What is an Urban Portal?

What Constitutes an Urban Portal and How Are These Used For Effective Division or Connection of Space and Circulation?

In this essay I will be examining the portal, in its definitions associated within the public realm and built environment, in attempt to open further study of a topic that seems to have been neglected to a certain degree. Whilst giving some definitions of urban portal types, I will try to fine examples within the context of my current city of residence, Glasgow (in conjunction with places I have visited or studied within Western Europe that have relevance), both from a user’s perspective and with technical analysis from a planner’s point of view, with reference to how the subject has been addressed in previous media.

E. White’s essay “Path-Portal-Place”1 has been influential to this study, yet I was not entirely satisfied with the definition or typologies he suggests. Although suggesting the experiential effects of passing through different types of portal, and diagrammatic explanation in drawn sketches, his lack of physical examples made it hard to fully appreciate the essay with respect to actual public realm. Although this may be deliberate for instance appealing to the reader’s own experience, I feel that if we are to analyse the built environment, it should be when possible within reality and not just theoretical.

The urban portal, as I understand it, invariably consists of an aperture in some form that allows the connection of spaces or paths to spaces within the public realm, and in some cases dictates a control over the accessibility of a space to different groups of traffic. What is important to understand is that these portals can shift in function very dynamically throughout the day and over the years, and dictated by the morphology of the surrounding built environment, but most importantly is that the portal has psychological and usually sensual influence on the user. The interpretation of portals is one that may be hard to establish immediately. A very basic analogy drawn from my rural background is the invisible, shifting constraints on a flock of sheep when sheepdogs are introduced to a field, the sheepdogs being visible to the onlooker but the perception of space by the sheep determining the movement of the flock as a whole, the space between the dogs forming a psychological portal. On a more physical level, the sheep entering a pen will pass through a gap within the fence of the pen, and in this case the portal is obviously visible. When all obstacles are removed, the sheep return to a dispersed state, bound by the realm of the field.

In establishing an urban portal typology I will first need to establish a criteria and method for examining suggested types of portals on the same grounds. I will of course be using plans to express conditions in a means that architects as well as anyone who has ever used a map can understand, but because of their reductive and diagrammatic nature, I will also be conveying the portal from a natural perspective such as seen by a human to show how these portals also function spatially. As I consider the portal’s aspect to be one of predominantly aesthetic and spatial qualities, I will be using photography as a key tool throughout this document. The immediate problem with this method, and one which I respect and understand but reproach in this context, is that photography reduces architecture and the “cityscape” to one of purely aesthetic qualities and not the full experiential effect that is created when the viewer is actually within the place and other senses are present, suggesting a lack of expression (such as S. Boeri’s argument, On Some Paradoxes in the Relationship Between Photography and the Contemporary City)2. Within this medium, however, I can find little to replace photography to convey the visual aspects of this topic. I should at this point insist that the photography I have used in this article is purely documentary and illustrative and not intended for reinterpretation, such as contemporary photography of the urban condition or early artistic photography now revered for its documentary qualities (for instance the work of Eugène Atget3, which documented the Parisian built environment before Haussmann’s extensive redevelopment of the city). This should be made clear with the use of overlaid annotation to express the interpretation I myself have associated with the photos. So, although I have found photography (and cinematography) influential in my analysis of the portal (and no doubt influences most people in urban society), I will be ignoring this avenue as it touches the well established subject of art influencing life, et cetera.

So to reiterate, it is my belief that the urban portal, although initially a seemingly limited subject, is nonetheless a subject that needs to be addressed, and a subject that represents one of the fundamental aspects of urban design. It is my hope that the types identified will be applicable to understand past, present and future design, and that they will be scalable to apply to all instances of portals from small pedestrian paths to wide boulevards within the urban context.

First of all I feel that the use of the word “portal” is appropriate to characterize these phenomena and will maintain it, as synonyms such as “threshold” have different connotations. Nomenclature will be ignored when analysing proposed types, as it is the actual definitions I will be trying to establish, not the names. Therefore the following avenues of investigation and research will be under the heading of either the cause or effect of the portal. What is also difficult to determine is where a portal becomes a space in its own right, or when a deep or extruded portal can become a path, which again blurs the boundaries of definition with personal perception. The types of portal established here will be linked to separate case studies, as during the investigation of types of portals I found that most portals had characteristic of more than one type I had identified, so I will start with the types identified so as not to be distracted by preconceived associations with the space.

Intentional & Accidental

The conditions under which a portal is established must be within a spectrum of strictly and consciously planned and entirely dictated by the natural effects of the place or subconscious application of design influence by the surrounding area. I call this a spectrum as I have not yet found examples that are the extreme of one or the other. Inorganic, grid street plan towns and cities such as Glasgow will often have disruptions within them that deviated from the plan, and result in effects that may not have been entirely predicted by the designer. Deviations from the contemporary development and morphology of the city can be established over a period of history either prior to or after the established portal and mark places that stay static in relation to the changing shape of the surrounding city. The ensuing associations with the portal such as historic events will be influential on the user’s experience of the portal. The knowledge of the history is essential for this effect, as without this knowledge the portal will have a completely different effect, but also may be a personal or private association to the portal with a personal or private event. The position of Glasgow’s Trongate marks a limit of the grid plan on the east of the centre, and would have been a historic physical portal for those entering the city. What seems true to Britain and Western Europe to an extent is that smaller towns such as the ones found on coastal regions which have grown slowly often have an organic plan resulting from the unplanned expansion of the town. In places where growth has been faster or in larger cities, master planning of developments has been more common, and often leads to the inclusion of portals in the course of the design process, and a more organised street plan, such as Glasgow’s (and other towns such as Helensburgh’s) grid plan streets, a concept that is derived as far back as antiquity in both western and eastern cultures4.

Official & Unofficial or Forced

When the public find that a portal is needed, for instance to connect two routes together, a new portal may be forced open, usually as a breach through a barrier. One example I have noticed of this type of portal exists on the south back of the River Clyde, opposite the SECC, where the public have found due to the otherwise long pedestrian deviation, that breaking a barrier that exists on the river bank gives access to both the continued river bank and a new diagonal route to the main road. As the routes through this barrier are marked by tracks in the bare earth, it is fair to say that these routes are neither planned nor officially condoned by any planning authority as a recognised route, yet it seems very interesting that the public is prepared to fix a problem formed by planning authorities with their own solution (Case Study I). Portals of this kind are most definitely physical rather than psychological, being routed in the public’s immediate physical requirements, yet extends the spectrum of intentional & accidental as being dependent on which point of view you take, the public or the authority.

Picturesque & Obscured

Some portals are designed with aesthetic effect in mind, such as to frame a particular view or create connections in space between one landmark and another. The medieval centre of Glasgow in and around Townhead has several landmarks grouped in a small area, including the Provand’s Lordship and Glasgow Cathedral. The addition of new buildings has led to the redevelopment of the urban fabric, most notably the St Mungo Museum of 1993 by Page and Park5. This building helps establish one of the most prominent portals in the area from a designer’s point of view, a framed view of Glasgow Cathedral from an angle, with a paved path offsetting the scene (Case Study V). This kind of portal is designed to entice the user through it, and in this case the constriction and subsequent release heightens the anticipation generated by the scene.

What make Glasgow interesting in this respect are the vistas created from the extended grid plan of its centre. Due to the nature of the topography on this grid plan, intersections create portals on four sides of a flat junction, each with a view of their own framed by buildings of near uniform height. Although there may be up to four extended views at any one place on Glasgow’s grid plan, the reality due to the human field of view is that a maximum of two routes will be simultaneously visible at any time. In other plans, the use of streets at acute angles to each other can increase the number of visible routes from a certain view point, creating several simultaneous portals.

Continuing with the theme of picturesque is the obscured, where for whatever reason the path or space beyond the portal is hidden from view. This can in some cases cause apprehension due to the uncertainty of what is around the corner or anticipation if the user expects to see something around the corner. Over time this effect will diminish for regular users as any initial surprise is replace by routine.

Materiality

Change in materiality, such as the paving material of a path will have a psychological effect on the pedestrian, as with the use of materiality in architecture. Often the materiality of the ground on the footpath and on the road will be contrasting, but can also be complementary, so any intersection of traffic use in a space will be heightened or dissolved with the presence or lack of materiality contrast. Places that have become pedestrians over the course of the life of the town or city result in spaces that can be shared by both vehicles and people in some instances, when the use of materiality breaks down. The related subject of balance and intersection of use will be discussed later in this document.

Level Change

To accommodate topography underlying built environment, planners in some cases have to arrange devices to connect the city over changes in height. This can create some intriguing effects, such as portals that appear to lead nowhere until approached, and superfluous portals that exist only to accommodate the connection of spaces at different heights (Case Study II). When routes start being developed on top of each other, portals are broken down and only the psychological effect of passing over or under a barrier is left (Case Study VIII).

Constriction & Release

Constriction and release can be used intentionally within buildings to create architectural effects, yet in the public realm this is usually as a form of control, and resulting from the use of the immediate spaces (Case Study IV). Constriction in vehicular traffic induces a reduction in speed and increase of congestion, enabling pedestrians to cross the vehicular path more easily (Case Study VI). Constriction to pedestrians is less common, but occurs in zones where vehicles are dominant. I will return to this subject later.

Physical & Psychological

One of the more important notions of the urban portal is the effect the portal has on us consciously and subconsciously. Physical portals are spaces we would instantly recognise as portals. These can often be iconic rather than functional, such as the classical triumphal arch or modern overhead sign. These serve as landmarks in their own right, and address our conscious thoughts. The opposite of these structures are psychological portals, which usually address our subconscious, such as the negative space formed by buildings or barriers. This use of the subconscious has been used for as long as urban spaces have been planned. Piazza San Marco in Venice holds characteristics that I think quintessentially e