The 5th International Conference of the International Forum on Urbanism (IFoU) 2011 National University of Singapore, Department of Architecture Global Visions: Risks and Opportunities for the Urban Planet

UPHILL NEIGHBORHOODS: Specificities and potentialities of urban fabric in sloppy

Adolf Sotoca & Oscar Carracedo

UPC-ETSAV, Carrer Pere Serra 1-15, 08173, St. Cugat del Vallès, Spain, Email:[email protected] UIC-ESARQ, Carrer Immaculada 22, 08017, Barcelona, Spain, Email:[email protected]

ABSTRACT: This paper introduces an unprecedented topic in Barcelona and its context. The strong identity of the draws up an iconic urban image of a plain smoothly reaching the seafront, but some important parts of the city are built over very sloppy hills. Although they present some specificities and many urban deficiencies resulting from their morphogenesis and physical conditions, there has been never an overall propositive approach to all these neighborhoods. The plan commissioned by the local administration to Adolf Sotoca and Oscar Carracedo is focused on this urban reality and points out some potentialities and strategies WKDWFRXOGSURYLGHDQHZXUEDQLW\WRZKDWFRXOGEHQDPHGDV³Barcelona on slope´

KEYWORDS: Barcelona, Urban Morphology, Social Justice, Urban Renewal, Informal Growing, City form and design.

1. BARCELONA ON SLOPE

The Eixample Cerdà in Barcelona is worldwide known as a paradigm of modern-planned city. Despite its conceptual cleDUQHVVWKHSDWWHUQGLGQ¶WVXFFHHGLQXUEDQL]LQJVRPHDUHDVRIWKHVRFDOOHG³3OD GH%DUFHORQD´7KHIRRWKLOORI&ROOVHURODDQGWKHPLGGOe hills of Tres Turons were so steep that they were set apart of an erudite project such as Eixample Cerdà. Instead of it, these territories became the first periphery of Barcelona, the result of non-planned urban processes. During the XIXth and the first half of the XXth century nothing prevented the low income and immigrant population from building their informal slums on this non-regulated territory. This process of informal urbanization resulted into a ³Vteep SHULSKHU\´RIWKHFLW\. The leap of scale from City to Metropolis that Barcelona experienced in 1953 and 1976 resulted into an intensive urbanization of a second periphery of the city. Mass housing states ±the so called Polígons- were built beyond the boundaries of the existing city. Demands for urban improvement and social justice in both informal slums and mass housing states have been explicitly expressed by dwellers since then. It was in 2005, when a residential building located in El Carmel felt down, that municipal authorities focused their attention on this neighborhood and some of the ancient social demands were for the first time in the urban agenda of the city. Since then some remarkable plans for El Carmel and its surroundings have been approved. Nevertheless, the approach to the issue was still partial and an overall survey to ³%DUFHORQD¶V steep SHULSKHU\´ ZDV PLVVLQJ 0RUH UHFHQWO\ LQ  D FRPPRQ DSSUoach to all these VORSS\QHLJKERUKRRGVDSSHDUHGWREHQHFHVVDU\VLQFHWKHODFNRI³%DUFHORQDVWDQGDUGXUEDQFRQGLWLRQV´ was more and more obvious. The ³6WUDWHJLF3ODQIRUNeighborhoods on slope´, which is still been drawn, proposes a morphological approach and tries to find links between social problems and morphological deficiencies.

Figure 1. Inhabitants per hectare in territories where slope is higher than 6%. The darker the area is pointed, the denser the urban fabric is in relation with the city density average.

2. MORPHOGENESIS AS METHODOLOGY

Once assumed that urban morphology and social deficits are somehow linked, the categorization of urban fabric on slope seems to be more than necessary. The steep, and most of the times dense, Barcelona is formed by a complex patchwork of urban fragments that, despite their common difficult relationship with topography, have very different attributes. That is to say:

x The grids on slope are the result of non-planned processes in which self-construction by settlers play a key role DQGFRQVHTXHQWO\WKHUH¶VDODFNRISXEOLFVSDFH7KHVORSHLVDFULWLFDOIDFWRULQWKHVH particular grids, since their integration (road system, public spaces and collective uses) in a wider urban context depends on it. We distinguish between half-flat grids, which are quite well integrated, and steep grids, which are segregated from the rest of the urban fabric. x The mass housing states were built, in most cases, beyond the boundaries of the existing city and designed as satellite neighborhoods. The so called Polígons are conceived as autonomous projects, both formally and in terms of urban management. Originally born as a planned response to WKHSUREOHPRIPDVVLYHPLJUDWLRQWRWKHFLW\GXULQJWKH¶- ¶- ¶WKHVHPDVVKRXVLQJSURMHFWV remarkably improve the living conditions of dwelling stock and increase the average of public space per housing unit in relation with the grid. For that, they prove to have enormous potentialities in terms of urban quality improvement. x The low-density urban tissues have similar difficulties to the grids on slope. Nevertheless, their environmental conditions can be better considered, as far as their lower density and the presence of private open space provide to these neighborhoods an extra value in comparison with the dense grids on slope. The weakness of urbanity and the optimization of public resources in low density areas are the challenges to be dealt in these areas. Low-density informal housing needs to be specially considered, since its urban deficiencies result also from their lack of basic infrastructure.

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Figure 2. Barcelona on slope taxonomy.

Figure 3. Location of uphill neighborhoods with higher density than the city average. Different colors refer to diverse categories of urban fabric attending to their morphogenesis.

3. HIPOTHESIS: AFTER URBANITY

Neighborhoods on slope have, still today, great deficits in mobility and collective facilities that place them as devoid territories of urbanity, lacking of essential and necessary conditions for a social net of UHODWLRQVWKDWLVWRVD\FLYLOLW\,W¶VKHUHVWDWHGWKDWWKHVHWRIEDVLFHOHPHQWVWKDWGHILQHWKHFLYLFGLPHQVLRQ of a Mediterranean city such as Barcelona are: x The street as basic support structure x Public spaces and collective facilities x Economic activities and commerce This paper considers these three topics for analysis and read the urbanity of neighborhoods on slope. We will infer some conclusions from the description of a defined case-study () in order to verify them in a larger city-scale.

4. NOU BARRIS, A PARADIGMATIC CASE STUDY

Nou Barris (NB) is a working-class district situated in the north-east area of the city. Mainly consolidated in the second half of the XXth century it is formed by an agglomeration of diverse neighborhoods (the English translation to NB is ³Nine Neighborhoods´). It was chosen as the first case study to analyze because NB is the only district in the city where all categories of urban fabric can be found.

4.1. Street pattern Figure 4 relates the urban fabric on slope categories with the occupation of private space and the street pattern. It can be concluded that in mass housing states the proportion of public space is well above the medium city average. On the contrary, for grids on slope and informal urbanization the percentage of street surface is well below. The problem is even worsened if the quality of the street pattern is considered, since most of the streets are quite narrow and with a very difficult and tortuous tracing.

Figure 4. Urban Fabric categories related to public space ratio.

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This deficiency leads to the necessary specialization of the road system in grids on slope. Unlike other areas in the city (where some streets assume the role of commercial space, civic axis and main channels for public transportation systems), in urban fabric on slope a strong functional specialization is clearly defined (fig 5)

Figure 5. Nou Barris: 3D scheme showing main roads with public transportation system and pedestrian roads with FRPPHUFLDODQGFLYLFXVHV7KH\GRQ¶WRYHUODSDWDOO

4.2. Tertiary uses Shopping activity is structured, depending on urban morphology, differently in NB (Fig. 6). From the commercial axis to the node of tertiary uses, a wide range of shopping structures can be found in this district. Based on morphological and functional features, they are: x City scale grid. That is the case of Via Julia a quite flat and continuous avenue, where civic and shopping uses that serve to a larger city scale are found. In Via Julia almost the 100% of the façade is devoted to shopping uses and a density over 12 businesses per 100 linear meters is quite common. Via Julia is the only commercial axis in NB where a certain public transportation facility is found. x District scale grid. Streets such as Joan Riera and Pablo Iglesias are also well integrated in the urban fabric but in a much more local scale. Percentage of commercial façade is in these cases between 70 and 80%, and the density of business per 100 meters is never more than 8. Flatness is, still, a necessary condition for the district scale grid. x Local axis, such as Carrer de la Mina de la Ciutat. Specific of steep grids, they are always segregated from the rest of the city and district scale urban fabric although they still function as civic centers of these urban environments. They commercial character is weaker than city and district scale grids.

x Shopping nodes where commerce activity is concentrated around a certain point of high accessibility. Considering its spatial configuration we state that commerce activity is intimately related with urban morphology. As shown in last conclusions, it is possible to trace a certain correspondence between shopping structure and the taxonomy established in section 2.

Figure 6. Nou Barris: 3D scheme showing shopping structure.

4.3. Collective facilities and public spaces Focusing on the main elements of inner urban structure an absolute lack of public space is pointed out for both informal housing ±Torre Baró- and steep grids ±Roquetes-. On the contrary, the central plaza appears to be the iconic and paradigmatic reference to traditional public space in housing states ±Canyelles-, as well as in many other housing states (especially in those of the second generation) in Barcelona. In half-flat grids ±Prosperitat- a rich and diverse amount of public spaces are displayed: from plazas to axis public spaces give structure to these specific grids like in many other traditional areas of the city. Although pedestrian character of plazas is very well known, there are also in half-flat grids some novelties concerning the pedestrian realm: in many local axes the car has been set apart in recent years and public policies tended to increase the domain for pedestrians. Those urban axes where public policies LQFUHDVHGWKHGRPDLQIRU³ZDONHUV´EHORQJDOZD\VWRWKHORFDOVFDOHVLQFHWKHSHGHVWULDQVpecialization of main axis was not compatible with collective public transportation flows. The most successful recently implemented pedestrian axis in NB fulfill two basic conditions: on one hand, it constitutes a continuous promenade which, passing through city scale roads, is able to link diverse neighborhoods. On the other, it is part of a more complex system of public space in which, together with local scale plazas and public facilities, a diverse and rich mix of social uses are found.

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Despite their civic character, commerce activity in these axes is usually missing. Basic conditions such as accessibility, outer spaces for consumers or specialized areas for goods loading are difficult to fit into the tiny dimension of these local streets, especially when other collective facilities are already pending on them.

Figure 7. Nou Barris: 3D scheme showing pedestrian roads, public spaces, collective facilities and shopping main axis. As seen, commerce activity and pedestrian public space GRQ¶WPDWFK

Regarding the relationship between street functional specialization and collective uses it can be stated that those roads whose main use is pedestrian orientated are the structural support for collective facilities. On the contrary, commerce activity is, still today, much more related with accessibility by car. Finally, a certain familiarity between functional specialization and urban morphology can be pointed out. x Public space axes are typical and specific of half-flat grids, since flatness is a basic condition for walking promenades and large facilities plots. x Commerce axis can be found in both half-flat and steep grids, as stated in point 5.2. Although shopping and walking are two intimately linked activities, business typology is far more flexible than FROOHFWLYHIDFLOLWLHV¶ ones. For that, even in steep grids, the presence of a local commerce axis is quite common. x The question of public spaces is handled in housing states in a much more specific-architectural approach. In these neighborhoods, conceived more as final stages than urban processes, the public sphere of the city is concentrated in agglomerations of seemingly urban centrality. Since the corridor-street is no longer in the basis of housing states, these agglomerations of urbanity can be hardly named as axes. Most of the times their structure refers to a node around a certain space of strong collective identity, such as a plaza. x Finally, informal housing lacks public space, collective facilities and commerce activities.

5. BARCELONA, TOWARDS A SYSTEM OF NEIGHBORHOODS ON SLOPE

5.1. Different streets, diverse neighborhoods, uneven urbanities Quantitative attributes such as street width or surface percentage are the reasons behind functional specialization in neighborhoods on slope in a local scale, as stated in point 4.1. On the other hand, other qualitative attributes of the street pattern, such as continuity or capability for urban structure, refer to a larger city scale. Figure 8 shows the relationship among urban morphology, street pattern and urbanity: x Half-flat grids are always related with civic axes and main public transportation arteries. These city scale systemic structures become spaces for local centrality and urbanity at the neighborhood scale. x Steep grids developed their own street pattern which has been always disconnected from the rest of city urban structure. For that reason urbanity in those neighborhoods has been in many cases sporadic and segregated. x Mass housing states, originally built in distant locations from the city center, are located next to very important (and recently enlarged) mobility infrastructures. This privileged location provides these neighborhoods an unprecedented regional scale centrality in which nodal urbanity and punctual access are the dominant pattern for commercial and collective uses in a local scale. x Informal housing, again, lacks urbanity since its extreme mono-functionality can hardly provide a physical frame where basic sociability could be displayed.

Figure 8. Uphill neighborhoods: Road system and urban morphology

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5.2. Places for transportation, spaces for exchange A cross-reading between urban morphology, commerce typology and public transportation system is established in figure 9. Two main conclusions can be inferred from that drawing: The first one relates commerce city-scale structure and its relationship with urban morphology on slope. It can be stated that: x City and district scale commerce grids correspond with half-flat grids, as far as main civic axes are not found in territories where slope is higher than 6%. x Steep grids have developed, due to their original isolation, self-sustainable local axis, which were pointed out in section 4.2. Although they become local centralities, they are totally segregated from the city scale commercial structure. x Mass housing states develop, according to their own morphogenesis, nodal tertiary uses polarizations. x Commerce structure in informal housing is missing. The second conclusion focuses on public transportation accessibility. It is stated here that in nodal polarizations and, specially, in half-flat grids, there is a direct relation between commercial intensity and public transportation accessibility. On one hand main public transportation arteries by bus match with central and civic axis in half-flat grid neighborhoods. On the other, all tertiary uses nodes in mass housing states are located around metro and railway stations. Local commercial axes, typical of steep grids, are not accessible by public transportation system. That notably reduces their target group of consumers and, for that reason, their urban vitality is extremely weakened.

Figure 9. Uphill neighborhoods: Public transportation system, shopping typology and urban morphology.

5.3. Metropolitan centralities, urban voids A first gaze to city scale structure elements points out a quick and easy conclusion: large scale public spaces and facilities are always fulfilling voids among neighborhoods on slope. Their relation is diverse: x Informal housing always grasps very difficult steep areas, where a close relation to the most appreciated metropolitan park ±Collserola mountain- could be possible. Nevertheless the borders between mountain and informal urbanization is something to be improve, as far as access to the park from these areas is, still today, extremely difficult. x Despite Mass housing states have similar access difficulties to Collserola, they include local public spaces that assure a certain environmental and urban quality. x Steep grids, mostly surrounded by dense urbanized areas, scarcely have some relation with city scale public spaces. The access to them is punctual and sometimes not clear enough and the local scale public space is mostly absent. For those reasons public spaces policies in these neighborhoods should be seriously considered. x Half-flat grids have clear and easy connection with city scale civic axes, although large public spaces are distant from them. In these neighborhoods, as in mass housing states, local scale public spaces are self-refereQFHGDQGLVRODWHGIURP³ODUJHVFDOHJUHHQHU\´ Going deep into the content of large public spaces another conclusion can be inferred: some of them are still non-planned territories where a certain program of uses and basic conditions for accessibility are still to come. Apart from that metropolitan facilities need to be, in some cases, gated areas where permeability seems to be more than impossible. For that reason these very important areas of the city turn to be urban voids instead of connectors. A reverse reading of the city, going from the void to the built up, appears to be an appropriate strategy to recover the full potentiality of these large scale public spaces and, by that, the extremely interesting value of unknown Barcelona on slope.

Figure 10. Uphill neighborhoods: City scale structure and urban fabric on slope: an intentional reading.