The challenge of urban sprawl
Density is one of the central issues in the recent debates about the urban future. The reason for that lies in the contradiction between the private and public interests in relation to the density of urban living: most actors (households, developers, businesses, etc.) strive to increase their individual, private benefits which, however, can only be satisfied at the expense of public interests. For example, most families prefer less dense urban forms, and their dreams result in sprawling suburbs which are very harmful from the perspective of sustainable urban development.
This contradiction between individual interests and their disastrous collective consequences is described as the ‘Tragedy of the Commons
’ (Hardin, 1968). The problem lies in the fact that the gains (returns) and the costs are neither accrued to nor born by the same actors. Moreover, the gains are often abstract and lie in the future while the costs are concrete and fall due in the present. This is a big challenge of the future: how can the – in the long run – more sustainable forms of (compact) urban development get more accepted by households, against their own immediate preferences.
This challenge is further complicated by the fact that density is not the only aspect of sustainable urban development. Sustainability in a broader sense should mean a dynamic balance between economic, environmental and social considerations. Therefore, in the end it is not density in itself that is interesting, but the relationship between the economic, environmental and social outcomes produced by different density levels. However, the environmental and social aspects of densification get often in contradiction with each other. Transitional areas are usually dominated by lower income residents, who are endangered by densification, at the risk of being pushed much further away from the central areas, and therefore with lower chances (and higher costs) to access inner city jobs. In that way the environmentally positive densification usually leads to negative social externalities, combined with the often occurring gentrification effects which decrease social mix.
Pictures 1-2. Suburb in the making close to Madrid in 2009; A typical transitional area in Rotterdam in 2016
The challenges of urban development – and among them densification, as one of the tools – are present in all growing cities. In a recent seminar
(Amsterdam, 2016) the case of the dynamically expanding Amsterdam was presented, which has to build 300 thousand new units by 2040. All traditional reserve areas (hospitals, military, etc) have already been used. Some reserve still exists in empty office and factory buildings and through densification, which would allow for 40 thousand additional housing units. For the other 260 thousand units only quite inconvenient options exist: super densification, demolishing 19th century areas in good shape; constructing on the green wedges (fingers), protected since many decades; or densifying Almere and the other new towns, outside the administrative borders of the city. Thus in the (extreme) case of Amsterdam the ‘normal’ practices of densification would not even be sufficient to answer the challenge of dynamic growth. Even so, densification (and keeping the already existing dense areas liveable) is unavoidable.
The sub>urban approach
The URBACT Sub>urban network
, led by the city of Antwerp
, followed by the Lead Expert Maarten van Tuijl
, concentrates on the urban fringe. This is defined as the often non glorious post war area surrounding the historic city, encompassing a mix of large modernist housing estates, low-density private housing, malls, logistical companies, recreational areas, businesses and industrial zones (van Tuilj, 2016). The aim of the network is to explore and compare the options to densify the urban fringe in an integrated way, taking both the physical and social characteristics into account. Densification through the „Regeneration in the urban fringe should be aimed toward mixed cultural and ethnic backgrounds and people of different incomes, education levels and ages. Therefore, the challenge also lies in spreading the benefits of growth and of regeneration equally and in providing affordable housing, jobs and facilities for all.” (ibid)
The conditions for densification of the fringe areas in the partner cities of sub>urban are not optimal, to say the least: the financial position of the municipalities is bad, the once dynamic public actors (e.g. housing associations) are in financial troubles, the banks are very cautious to invest in anything. On the top of all these in most cities properties in the fringe area are privately owned, both by big corporations and private households, thus the planning influence of the municipalities can only be indirect and limited.
Under such circumstances cities have to find new, innovative approaches to achieve their strategic aim, the densification of the urban fringe in an integrated way, i.e. avoiding negative social and environmental externalities. The general approach of sub>urban is described here
Below, I describe how 4 of the sub>urban cities try to engage all potential stakeholders, such as owners of land and buildings, investors, developers, residents, workers and potential newcomers in their strategies.
experiences a strong population growth outside the inner city. It has selected 7 action planning areas from the large territory of the urban fringe, with very different challenges and identities. Lageweg, a formal industrial site, is one of them. The area is characterised by a high number of owners with small plot sizes. There, the municipality applies specific pilot measures to speed up the development process (van Tuilj, 2016
). It organises activities such as mind opening dialogues and kick-off discussions to explore collective ambitions for the area, co-creative design tables involving an interactive scale model of different scenarios in order to build collective trust, guided walks with all stakeholders with a brochure showing possible future scenarios, adaptable spatial and financial calculation models to test the feasibility of several options. Thanks to these tools most of the land owners were gradually convinced and decided to sign a declaration of engagement to work and invest together in the project. The success of the initiative was that it allows to work across property borders and to make an effective plan for the whole area, for a step-by-step development.
wants to solve the conflict of dynamic growth versus spatially limited urban area (the city is surrounded by highly valued green belt which can not be touched) by densifying former monofunctional industrial areas, within the city border but outside the city core. 5 pilot project areas are selected to test a new process, with the objective to make transformation more flexible. The city focuses on the essentials and leaves room for private parties to come up with their own ideas. A Planning Program defines general guidelines, urban development principles and rough parameters for land use, height and utilization (van Tuilj, 2016). This is extended by a Principle Plan for the Public Space, which defines the boundary, size and desired qualities of public spaces, identifies and describes public projects and builds in a certain flexiblity, so that market parties can fill in the rest.
has been characterized by heavy suburbanization in the last two decades. To mitigate that, the city is looking for opportunities of densification within the city border. Two action areas have been selected. They are relatively close to the city centre (10 minutes by tram). A dynamic university campus has been built in the area, which is still surrounded by little gardens. Some of the gardens are already abandoned as the owners know that the area will change: the future use will be housing – although no infrastructure and transport links exist yet. Brno municipality decided for an experimental approach instead of the usual top-down decision-making. As a first step links have been created between the relevant municipal departments, the mayor and the 3 affected district mayors. Nearby residents were waiting for the municipality’s ideas (e.g. immediate re-zoning) and were prepared to oppose these. To their greatest surprise they were approached by the municipality and asked about their ideas. This new type of planning process is unusual in post-socialist cities, it has to be explained not only to the different units of the city and district administrations but also to the politicians. The URBACT project and the need to create Local Support Group was a good occasion to start this journey towards an uncharted territory in policy-making.
is the largest municipality in the northern Naples area, only 10 km away from Naples. The population (around 78 000) has been decreasing in the last two decades. From the late 1970s on, Casoria has lost its role as major industrial centre: production activities stopped, factories and industrial sites were abandoned. The city developed a strong services sector but today even the services sector finds itself in crisis. Local residents are leaving the area due to traffic congestion, unemployment, low quality settlements, poor quality housing, inadequate infrastructures (roads, facilities) and lack of public green space (see Sub-urban Baseline Study
, 2016:95). In Casoria, the need for densification comes not from urban growth or suburbanization but from the high number of underused areas and buildings from the industrial and services sectors and from the plans of the municipality to create large suburban public parks. The city promotes flexible planning in transparent arenas, testing tactical urbanism. Instead of top-down decisions, the public administration wants to work with private owners and city users (associations). Cooperation with other municipalities is planned towards a strategic plan beyond the municipal borders.
The four cases show the different circumstances and reasons under which densification of the urban fringe might become an important aim towards more sustainable urban development: not only in dynamically growing cities (Antwerp, Oslo) but also in stagnating (Brno) or even shrinking (Casoria) cities. These cases also illustrate that cities have to start dealing with their transition areas even before having completed the regeneration of their inner cities. Even if inner city renewal is unfinished, to continue it might be very costly and cities may decide to change priorities towards cheaper interventions in the transitional belt, where more flexible approaches are possible.
Sub>urban in action: Messages for the Future of Casoria
The Casoria transnational meeting of the sub>urban network included discovery walks of the city in small groups and provided the opportunity for partners of the network from other cities to leave their messages for the future of Casoria. Have a look!
Pictures 3-4. The urban walk in Casoria: the map and the group underway.
Pictures 5-6. The sub>urban group in Casoria’s largest brownfield area.
The walk was followed next day by an urban gardening action in the course of which all partner cities got the opportunity to plant a tree and leave in this way their message for the future development of Casoria.
Pictures 7-8. Urban gardening and peer review discussion about the Local Action Plans in the Contemporary Art Museum