Scale

Fundamental to any urban and architectural analysis is a consideration of the physical attributes of a space, including its quantitative parameters (size/scale), and its geometric features (configuration and form). Alongside their anthropometric and legislative imperatives, urban environments are closely related to the senses and behavioural patterns of those who use them, and this is important to understanding how they are perceived. Beyond measurements, the notion of scale should be understood as a correlation between the size of a space and the anthropometric parameters of its users, as well as with other physical objects, such as buildings (Lynch, 1971). There are two ways to assess the scale of a public space: from the perspective of its users, and from the perspective of the city. The former prioritises anthropometry (human senses), and considers the relationship between the public space and its users, while the latter addresses the ratio between the size of a public space and the extents of the city.

In the human, user-oriented perspective, the key to successful urban planning lies in finding adequate methods with which to measure the human scale and transpose it into urban design. In 1966, American anthropologist Edward T. Hall introduced the concept of proxemics, 28 and defined four spatial spheres relative to the human sensory apparatus: intimate, personal, social and public. Urban design and planning disciplines emphasise the importance of the social and public spheres. The social space, ranging from 1.2 to 3.7 metres from ourselves, is the zone in which we greet others and communicate informally. Distances beyond 3.7 metres are public space, in which we can observe and be

28 Proxemics is the study of the spatial requirements of humans and animals, and the e ects of population density on behaviour, communication, and social interaction (https://www.dictionary.com; Retrieved March, 2019).

observed (Hall, 1966). Using Hall’s reasoning, urban scholars such as Alexander, Gehl and Lynch sought to determine the optimal dimensions of the public space. Most subsequent approximations were based on the correlation between the human senses and the aforementioned definition

of social space. According to Lynch, public spaces within a range of 12 metres can be described as intimate, while all those that measure up to 25 metres fit the human scale. Many of the successful enclosed squares of the past did not exceed 140 metres in length (Lynch, 1971). Gehl combines perceptive, psychological and social factors to determine the extents of the so-called social field of vision. The upper limit of the field, measuring 100 metres, was defined by the maximum distance at which a human figure can be perceived. From between 70 and 100 metres it is possible to determine particularities such as a person’s gender, or what that person is doing. This corresponds to the range of visibility on many sports fields. Another threshold was at approximately 30 metres, from which some more pronounced physical features, such as age or hairstyle, can be recognised. Only at a distance of 20 to 25 metres is it possible to perceive, relatively clearly, the feelings and moods of others. In his elaboration of the relationship between a place’s scale and intensity and closeness and warmth, Gehl states that smaller cities and projects are commonly perceived as warm and intimate, while large spaces are experienced as cold and impersonal (Gehl, 2011).

The correlation between the small scale of an urban space and its sense of intimacy is easily identifiable in Sarajevo’s Ottoman old town. The urban and architectural design of open and enclosed public spaces in this area were intuitively affected by the human scale, and can be perceived in the context of both Lynch’s and Gehl’s description of intimate urban spaces (Figure 20).

Figure 20. Juxtaposition of pedestrian and vehicular scales in urban morphology of Sarajevo. Left: Ottoman small-scale meets Austro-Hungarian medium scale in the old town of Sarajevo. Centre: Austro-Hungarian meets socialist Yugoslav and contemporary medium and large scale at Marijin Dvor. Right: Automobile scale (medium and large scale) of socialist Yugoslav urban areas in the municipality of Novo Sarajevo.

It is important to note that prior discussions on the perception of different urban scales use an average movement speed of 5 to 15 km/h, relative to a pedestrian walking or running.29 The perception of a space changes considerably with vehicular movement. As Gehl claims, “[the] automobile city and the pedestrian city have quite different sizes and dimensions” (Gehl, 2011). This implies that all urban representations are enlarged, in order to be perceived from a car moving at an average speed of 50 km/h. In Sarajevo, Mesa Selimovic Boulevard illustrates the automobile city scale. This eight-lane road, located in the high-density socialist residential area of Alipasino Polje in the city’s west, features massive concrete towers dating from the 1970s, as well as recent largescale developments of postmodernist public buildings on its south side. To the north of the boulevard is the 300-metre-long brutalist Radio and Television of Bosnia and Herzegovina building, surrounded by vacant plots that await development. Because its activities, communications and functionality are dispersed, the area lacks urban coherence. Despite local government efforts to introduce diverse public amenities in the pedestrian zone alongside the boulevard, such as seating, urban greenery and a bicycle and jogging path, this area has failed to respond with increased urban activity.

We can also compare the size of the public space to the size of the city. In this sense, the notion of urban density30 is relevant, as it acknowledges

29 This means that an average pedestrian would be able to walk approximately 800 metres in 10 minutes.

30 It is a common perception that high density and quality of life are mutually exclusive in urban public spaces. Various (mostly unsuccessful) attempts have been made to capture the relationship between the quality of an urban form and its density. On one hand, we have simple progressive calculation methods such as the New Urbanist concept of transect planning, which suggests proportions of green and grey space relative to the progressive growth of urban density (Duany, et al., 2009). On the other, many authors (E.R. Alexander included) underline the interrelation of density and other factors, and note that the concept of density is complicated, as it involves “… the interaction of perceptions with the concrete realities of the built environment” (Alexander, et al., 1988). To this purpose, it is important to consider two types of density: 1. Building density, or three-dimensional density, which is measured by the Floor Area

that public space is directly dependent on urban context and urban form. Some theorists propose overlapping the notions of scale and social implication to serve a larger or smaller percentage of the urban population. It defines three levels of scale: citywide, intermediate and residential. The city scale refers to open spaces associated with the main institutions of the city, and is oriented to a larger population. The intermediate scale relates to spaces that serve collective residences in a more localised portion of the city, such as a district or neighbourhood. The third level, residential, refers to small-scale public spaces in areas with single-family houses or smaller residences with shared spaces for occupants, such as yards or enclosed courtyards (Stanley, et al., 2012).

Based on the theoretical guidelines previously discussed, in correlation with the specific geomorphological features and urban scale of Sarajevo, we have identified and mapped (Figure 21) three categories of public space, varying in their size and urban level, with matching quantitative criteria:

1. Large- and extra-large-scale urban public spaces and zones (XL and L spaces), larger than 100 metres; 2. Medium-scale urban public spaces and zones (M spaces), from 25 metres to 100 metres; 3. Small and extra-small-scale public spaces and zones (S and XS spaces), less than 25 metres.

Ratio (FAR) index. It is expressed by a building’s total number of square metres divided by the total square metres of the lot it stands on; and 2. The correspondence of urban density to the heterogeneity of land use and function. This is expressed by the urban density index, which is the ratio of the area (in square metres) that functional land use occupies to the build surface for each city block, multiplied by a diversity factor. Values of 100 or more indicate greater diversity. Generally, the second type of density relates to the traditional planning apparatus, and even though it is based on functional diversity it does not necessarily guarantee the quality of a public space.

lightest shade stands for the XL spaces while darkest one represents XS spaces. Figure 21. Mapping of urban public spaces in Sarajevo by their size. Urban scales from XL- L-, M-, S- to XS are graded by the colour shade: the

Areas in the first category, large- and extra-large-scale public spaces and urban zones, are found in the northern and western areas of Sarajevo, and usually date from the Socialist Yugoslav period. Compared to those in the other two categories, L and XL spaces are encountered less often, generally because the city’s mountainous topography impedes the development of larger open public spaces. Urban mapping therefore indicates that the category containing the largest open public areas has only a few examples of large-scale recreational zones, located in the north and far west of the city. One of the most significant of these is the 2-kilometre-long Wilson’s Promenade, which stretches along the banks of the Miljacka River in the municipality of Novo Sarajevo.

At first glance, the scope of XL and L spaces include large-scale modernist residential blocks,31 as well as some postmodernist urban blocks in the Novo Sarajevo and Novi Grad municipalities. These blocks are often located in heterogeneous parcels, consisting of large open spaces and multiple buildings arranged in a free layout. They typically feature modernist arrangements of freestanding buildings, which are occasionally on pilotis and appear to be floating in the fluid, open space of their park-like setting. Despite the modernist ideal of creating large common spaces as a foundation for architectural development, deconstruction of the patterns of use of large-scale socialist residential blocks reveals that they are in fact compound areas, made up of multiple medium- and small-scale fragmented open public spaces (Figure 22).

Examples of medium-scale and small- and extra-small-scale public spaces can be found throughout Sarajevo, although the latter is most recurrent. Urban mapping highlights the prevalence of this category in the dense urban tissue of the city’s historical core, in the form of small interior courtyards or atriums concealed behind introverted Ottoman structures. Following the enlargement of the urban scale of districts in

Figure 22. Enlarged map showing public spaces of various sizes in Sarajevo. Left: Medium and small-scale public spaces are dispersed in the residential neighbourhood Hrasno. Right: Sarajevo University campus encompasses largescale public spaces. Bottom right: Radio and Television of Bosnia and Herzegovina headquarters is accompanied by extralarge open public areas.

the 19th and 20th centuries, the interior courtyards of Austro-Hungarian residential and public urban blocks were mapped as either active or potential medium-scale public areas. Because of their size of up to 100 metres’ range, all public squares and pedestrian streets were recorded as medium-scale public areas. The largest squares in Sarajevo, Skenderija Plateau and Parliament Square,32 were classified as medium-scale open public spaces as they do not exceed the 100 metre range and are smaller than some renowned European squares (Figure 25).

32 Average areas of the most prominent squares in the downtown and old town of Sarajevo: Children of Sarajevo Square (BBI) 3000 m2; Parliament Square 5500 m2; Skenderija Plateau 5600 m2; Theatre /Susan Sontag Square 1800 m2; Oslobodenje/Alija Izetbegovic Square 6200 m2; Sebilj/Bascarsija Square 1800 m2 .

Figure 23. Distribution of medium-scale (M) urban public spaces in Sarajevo.

Figure 24. Distribution of small and extra small-scale (S and XS) urban public spaces in Sarajevo.

Venice Brussels Lisbon

Skenderija Plateau Sarajevo: Children of Sarajevo Square Parliament Square

Figure 25. Comparative view of the squares in European cities and the squares in Sarajevo: San Marco in Venice, Grand Place in Brussels, Praca da Commercio in Lisbon with the Skenderija Plateau, Children of Sarajevo Square and the Parliament Square in Sarajevo.

Scale: Summary

The objective of assessing scale by means of urban mapping was to determine the varieties, distribution and recurrence of the different sizes of public spaces in Sarajevo. The subject was approached from two perspectives simultaneously – the city scale and the human scale. The dimensional ranges to define public spaces were obtained from theoretical sources and empirical research, particularly from the study of anthropometrics and human senses. Specifically, Edward T. Hall’s discussions on proxemics, Kevin Lynch’s assertions on the optimum size of public spaces, and Jan Gehl’s concept of the social field of vision provided the theoretical background for categorising public spaces by their scale. After being tested in the urban framework of Sarajevo, the proposed classification of public spaces by scale was structured in three levels: 1) large- and extra-large (XL and L); 2) medium (M); and 3) small- and extra-small (S and XS).

The study shows that small-scale public spaces are intuitively attuned to the human scale, and their distribution corresponds to the chronological layout of the urban scale of Sarajevo’s neighbourhoods. This means that

S and XS spaces mostly appear in the oriental Ottoman old town, while M spaces are generally located in occidental Austro-Hungarian and Socialist Yugoslav areas. Urban mapping shows that XL and L spaces, though largest in size, are the least recurrent typologies, and are typically associated with the “automobile city scale” urban areas, which were developed in the second half of the 20th century. The most prevalent categories – M and S spaces – can primarily be identified as traditional public spaces (“green spaces” and “civic spaces”, such as parks, plazas, squares and streets. The superimposition of urban maps that focus on the scale and function of public spaces has revealed the occurrence of peculiar medium-scale areas, sometimes referred to as “undefined spaces”, in two forms. The first is the compact, enclosed space, such as the interior courtyards of Austro-Hungarian blocks, and the second is the fragmented segments of open space in modernist blocks. Both are suitable for transformation into public spaces.

The results of the study of scale of public spaces in Sarajevo shifts the focus of future research and planning to the level of small- and mediumscale spaces, as “… the small scale – the immediate environment – is where the individual person meets and evaluates decisions made at all planning levels. The battle for high quality in cities and building projects must be won at the very small scale, but preparations for successful work at this level must be made on all planning levels” (Gehl, 2011).