Keywords

1.1 Introduction

This book within the Sustainable Urban Futures series treats an age-old topic. Urbanization can be understood as the intensive concentration of people and human activities into a small area as well as the land-use changes made to support this concentration. It is an integral part of human history and civilization since the first cities emerged in Mesopotamia during the fourth millennium BC (Kostof, 1991; Mumford, 1961). In Europe, urban history began in Greece and then in Rome, the latter’s capital reaching an estimated population of nearly 1 million during the reign of Augustus (Carcopino, 1943, p. 18).

The desire to manage urban growth for the public benefit is as old as cities themselves. Urban design and planning strove to ensure accessibility, reserve space for public use, and separate incompatible functions. For example, outside Rome’s city walls was the so-called suburbium, the domain of industries that could not be accommodated in the city and of poor residents who could not afford to live in the city, but also of the elegant villas of the Roman elite atop hills or near the coast (Bruegmann, 2006, p. 26). During the seventeenth and eighteenth centuries, elites of affluent cities like London and Amsterdam also bought land at a comfortable distance from the city to build summer (and sometimes permanent) residences. The construction of railways in the nineteenth century accelerated this process, resulting in the first commuter suburbs (Couch et al., 2008, p. 11; Hall, 2014). The first half of the twentieth century saw the genesis of modern planning. Amsterdam and Copenhagen adopted ‘finger plans’ with protected green wedges between districts, while London’s appetite for urban growth was tightened by its famous Green Belt (Kühn, 2003).

The Second World War marked a turning point. Car ownership in combination with growing prosperity allowed the suburban ideal to be enjoyed by an increasingly greater number of people in the Western world (Jackson, 2006). In Europe, the 1960s and 1970s were the heydays of suburbanization, often in the form of planned communities. For the first time in centuries, more families were leaving cities than arriving, plunging the cores into socioeconomic and fiscal crises, aggravated by deindustrialization (Anderson et al., 1996). Alerted by the massive report The Costs of Sprawl in the US (Real Estate Research Corporation, 1974) and similar findings in Europe, politicians began to worry about the effects of uncontrolled urbanization. In the United States, some states implemented growth management strategies (Carruthers, 2002) while Europe largely mobilized existing planning traditions to manage urban growth. By the turn of the millennium, most major American and European cities had recovered from the urban crisis and started to grow again, both in population and in wealth (Dembski et al., 2021). Yet the urbanization of rural hinterlands, coastlines, and along infrastructure continues.

Today, the policy discourse on urbanization in Europe is largely framed by the concept of sustainability, usually by pitting compact city ideals and transit-oriented development against the menace of rampant, land-consuming urban sprawl (Bruegmann, 2006; Roo & Miller, 2019). Especially in Europe, there is a concern that current land-use practices are undermining long-term economic prosperity, social cohesion, and ecological vitality (Hennig et al., 2015; Jehling et al., 2018). The European Environment Agency has called urban sprawl ‘the ignored challenge’ (EEA, 2006), and the European Union has adopted a goal to reduce net ‘land take’ (i.e. greenfield development) to zero by 2050 (Science for Environment Policy, 2016).

The twin notions of ‘urban sprawl’ and ‘land take’ are powerful metaphors. They are also, partly for this reason, rather poor analytical terms for conducting scientific research. Both are inherently normative and pejorative. Moreover, ‘urban sprawl’ has the additional disadvantage that the attributes of the phenomenon are regularly confounded with its perceived causes and effects (Galster et al., 2001). Consequently, as much as possible we will refer to the phenomenon whereby land is converted from rural to urban use as urbanization and describe its manifestation (e.g. density, shape) using neutral terminology.

This book aims to provide a general and contemporary overview of knowledge on the sustainability of urbanization in Europe, contributing to both the academic literature on the topic as well as providing insights for practitioners and students. It is largely built on the empirical evidence produced in the ESPON project Sustainable Urbanization and land-use Practices in European Regions (SUPER) (Evers et al., 2020).

1.2 Conceptual Framework

The process of urbanization and its relation to sustainability is the central theme of this book. The remainder of this introductory chapter will discuss the conceptual framework underpinning the thematic chapters (Fig. 1.1). As illustrated, we conceive of urbanization as a causal process involving inputs, a decision-making arena, and outputs. The totality or parts of this process can be assessed in terms of sustainability.

Fig. 1.1
A block diagram depicts the sustainability assessment of urbanization and land use drivers, demand, supply, institutional, territorial context, practices, and outcomes in European regions. It includes quantitative and qualitative assessments, focusing on land-use changes impacting the economy, society, and environment.

Conceptual framework

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1.3 Drivers of Urbanization

We begin the discussion with a consideration of the causal factors (drivers) of urbanization. An important starting point is a review article that compiled the most important factors cited in the academic literature contributing to urban development (Colsaet et al., 2018). Their findings are displayed in Fig. 1.2. These concern both relatively autonomous factors such as economic, demographic, and cultural developments as well as public-sector interventions that directly (e.g. land-use plans) and indirectly (e.g. fiscal policies) help determine where and how much land is converted to urban use. If we consider the urbanization process as a system of land development, we can then make a distinction between those factors which cannot be easily influenced by public-sector interventions (exogenous, labelled as ‘other factors’ in black) and those which comprise part of the system (endogenous, labelled as ‘policy and institutional factors’ in white). These factors will be discussed below using slightly different groupings and terminology.

Fig. 1.2
A block diagram illustrates factors influencing reliance on local taxes and land use, including planning capacity, subsidies, transport infrastructure, and population growth. It details the effects on land demand, supply, global land take, and localized impacts.

Drivers of urbanization

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1.3.1 Exogenous Drivers

  • Demographic change. Population growth is strongly related to urban growth because people need somewhere to live. Regions with a shrinking population are more likely to exhibit deurbanization, the conversion of urban land to natural or rural areas. Migration is an important element in this, but hard to predict. Demand for housing is furthermore driven by household development, which may show different tendencies than population development. In many countries, average household sizes are decreasing significantly, meaning that more homes are needed per capita. In Amsterdam, for example, the average home had about 4.5 occupants at the end of the nineteenth century, but a hundred years later this number had shrunk to under two even though the floorspace of the average home had increased (Wintershoven, 2000, pp. 128–129). In this situation, cities must physically expand just to retain their population.

  • Economic change. Rising prosperity allows for more individual consumption of space: larger houses, gardens, parking space for cars, and perhaps even a second home. Job growth also implies more room for commercial development, be it offices, industry, or retail. Here too there is a clear relationship with urban development. Industrialization created a logic whereby workers were located near factories (themselves often located near rivers or natural resources) or well-connected by transport infrastructure. Deindustrialization broke this relationship, and the advent of the knowledge and creative economies created new preferences for business and residential locations. Arguably digitization, fuelled by the Covid-19 pandemic, has again altered this driver: homes and cafes have now become workspaces.

  • Culture: The demands placed on the home and its surroundings are also a matter of taste. Cosmopolitans or young professionals tend to prefer urban settings, while other groups such as middle-class families tend to prefer more suburban environments. These preferences can be highly unpredictable and vary over time or space. Indeed, people can change their minds about the ideal living situation quite often throughout their lives. Still, some societies tend to have more stable preferences, as can be read in the locations where the cultural or economic elite tend to congregate. During the Covid-19 pandemic, there was great speculation about whether this event would have a lasting imprint on housing preferences.

  • Physical constraints: The availability of buildable land is another determinant of urbanization; the density of Manhattan Island or Hong Kong can be partly explained by the fact that the only space to develop is usually upwards. Steep slopes can also thwart expansion, and many mountainous settlements run the course of their valleys. Some physical impediments are manmade, such as the Berlin Wall or West Bank Barrier or, less dramatically, the dividing effect on neighbourhoods of highways running through cities. As byproducts of land-use decision-making, this last type can be seen as straddling the distinction between exogenous and endogenous factors.

1.3.2 Endogenous Drivers

  • Infrastructure: Transport infrastructure, as shown in the figure, is a driver both on the supply and demand side. Its provision increases the attractiveness of nearby locations for urban development due to the enhanced accessibility. It can also act to increase demand for housing and commercial space as it facilitates agglomeration economies. The advent of rail transport (train, tram, underground) allowed for the extension of cities far beyond their former borders, whereas the shift to the private car accelerated urban expansion to unprecedented levels (Antrop, 2004). More recently, broadband networks and mobile communication have been studied as factors shaping the growth of cities (Graham & Marvin, 2001).

  • Finances: land development is often an important source of revenue for local authorities, either through property taxes or by taxing or participating in the project itself. A common phenomenon is inter-municipal competition to attract development, which can undermine planning efforts (Knox & McCarthy, 2005). In addition, housing demand is driven by subsidies for affordable housing, tax relief to homeowners, etc. (Burchell et al., 1998; Nivola, 1999). Therefore, this driver can be seen as the legal and fiscal systems which determine the financial payoffs of development (Buitelaar & Leinfelder, 2020; Rothenburg, 1978).

  • Spatial planning: National and regional/local spatial planning systems influence the process of urbanization (Couch et al., 2008). The ability to control urban growth depends on the institutional setup, such as the powers and responsibilities of planning authorities (Pagliarin, 2018). There are a variety of potential ‘interventions’ that can be applied in this regard, such as regulation (e.g. zoning, generic rules), public investments (to encourage regeneration, and densification), and persuasion (strategies that bind and commit relevant stakeholders).

1.4 Land Development Practices

As a next step, we acknowledge that, barring illegal or informal development, these drivers are not directly determinative of urbanization, but instead structure or inform an official decision to allow a particular parcel of land to change use. In this decision-making, other factors can come into play than the drivers listed above, such as local politics. It is a ‘black box’, which can only be investigated with in-depth case study research.

Nevertheless, a few commonalities can be identified for most major land-use decisions. In many cases, a strategic document is drawn up stating the challenges facing the region and formulates general objectives, usually following a public consultation or debate and some coordination between governmental offices. Ideally, local plans should be in line with this strategy, but in some cases, there is a mismatch, especially in cases where unbuilt land is given urban development rights (it is easier—and cheaper—to grant than remove rights). Spatial strategies can exist at various levels of scale, and are not always coherent or consistent, partly due to continually changing circumstances.

Most of the time, planners or public officials do not initiate urban development, as this is often lucrative enough for the private sector. If no development rights exist, a property developer will typically request planning permission or a zoning change, sparking an official process to evaluate this proposal. This can involve checks for compliance with European or national policies, environmental impact evaluations, marketing research, site visits, public consultation, financing arrangements, and the like. Depending on the size, location, and interests at stake, it can involve stakeholders at various levels of scale creating a highly complex decision-making environment. In addition, the site in question can change hands multiple times in the process as land transactions are made to facilitate the development (municipalities in some European countries have the practice of buying land on the urban fringe to guarantee they are in control of urbanization). The final decision to approve the project is usually both a political/official decision (and hence dependent on a certain level of public approval) as well as a legal decision (and hence subject to legal rights to appeal). It also is fraught with dilemmas regarding core beliefs about democracy and property (Davy, 2016; Foglesong, 2015).

The above account is of course a vast simplification; every European country and territory within it has its own variation on the ‘development game’ depending on the exogenous and endogenous driving forces. While it is not always possible to peer into the black box of these practices, their result can be read in the structure of and changes to the natural and built environment. It is to this that we now turn.

1.5 Urbanization Outcomes

Many variations of contemporary urbanization can be distinguished in Europe, from faux historical tourist-oriented projects in traditional villages to massive holiday complexes, datacenters and logistic hubs, luxury apartments on former industrial land, out-of-town shopping centres and strip malls, edge cities near major airports, ecovillages, leafy suburbs, university and health campuses, scattered holiday homes in coastal and mountainous regions and even deurbanization (conversion of urban land to natural or rural uses). Most developments require ample road and parking space, but others cater to alternate transport modes. Some developments include large tracts of public open spaces and services, while others are oriented towards private green spaces and self-sufficiency. Viewed from above, some new developments are coloured completely ‘grey’ from the cement, rooftops, and asphalt, while others are so green as to be barely distinguishable from a forest or countryside.

To align with, but also break beyond the common compact versus sprawl dichotomy, we, following others (e.g. Anderson et al., 1996; Rice, 1978), discern three archetypical modes of urbanization to be used throughout this book. These are: compact urbanization (i.e. high-density compact cities, often the result of urban containment strategies or geographical limitations), polycentric urbanization (i.e. clustered, medium-density urbanization, often the result of policies like new towns, smart growth, transit-oriented development, and new urbanist designs) and diffuse urbanization (i.e. low-density scattered urban development like monofunctional car-oriented suburbs, ribbon development and exurban, often informal, construction, often the result of inter-municipal competition, and laissez-faire planning). Other urbanization modes certainly exist, but we concentrate on these three for the sake of analytic clarity. For the same reason, even though we acknowledge that these modes are not mutually exclusive and can be combined in practice, we use them as discrete types in our analyses (Fig. 1.3).

Fig. 1.3
Three illustrations depict urban forms. Compact, Polycentric, and Diffuse, each represented by a surface map. Additionally, three photos visually demonstrate these urban forms.

(Source Icons drawn by Kersten Nabielek [PBL] for the SUPER Guide to Sustainable Urbanization [Cotella et al., 2020], Maps produced from Corine Land Cover [CLC] depicting Loire [F], Modena, [IT], Flanders [BE]; Photos: Google Maps 3D views of Valencia [ES], Leidschenveen [NL], Zagreb [HR])

Compact, polycentric, and diffuse urban form

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1.6 Sustainability Assessment

The original definition of sustainability in its current sense regards a temporal balance, that is the ability to ‘sustain’ the quality of life on the planet, which ties into notions of generational justice (WCED, 1987). Temporal measures of sustainability often use the notion of ‘carrying capacity’ to assess whether resource consumption exceeds the recovery rate (Neuman & Churchill, 2015). One could argue that land, as a finite resource, can never be sustainably ‘consumed’ by definition—a notion that is implicitly suggested by the term ‘land take’. A less austere view would be that urban (re)development enhances sustainability if it creates a more future-proof urban form or if it accommodates human demands as efficiently as possible. A final consideration concerning temporal sustainability is the durability of policies over time (e.g. stability of funding, vulnerability to political/economic cycles) and governance quality and capacity to effectively steer long-term processes such as urbanization. We call this institutional sustainability.

Another common conceptualization of sustainability regards a thematic balance, usually between three dimensions, commonly referred to as the ‘three Es’ (economy, ecology, equity) or the ‘three Ps’ (people, planet, profit). Sustainable development, therefore, advances one or more of these dimensions without sacrificing the other. Urban planning and urban design often try to improve all three simultaneously (Campbell, 2016). Given that social and environmental interests are traditionally the first to be sacrificed, the thematic conceptualization of sustainability has been recast as a ‘donut economy’ where economic development occurs within social and planetary boundaries (Raworth, 2017). This is also the stance taken by the United Nations, which uses the three dimensions to argue that: “urbanization processes should benefit, not handicap, all residents who live in urban areas. As a transformative force, sustainable urbanization should accelerate the ability of governments to meet the diverse needs of residents’ lived experiences, aspirations and wellbeing” (UN Habitat, 2020, p. 45).

Given these two conceptualizations, we can then ask ourselves various questions about urban development in Europe. To what extent and under which conditions can a given amount of land converted to urban use (urbanization/land take) be considered sustainable? How can the right balance be found between dimensions of sustainability? To what extent are current development practices a product of exogenous driving forces? The answer to this last question can provide cues towards drafting interventions to adjust the parameters towards a more sustainable urban future.

1.7 Plan of Book

The chapters follow the same logic as the sections of this introduction and the conceptual framework, but in a slightly different order because some information is more useful as a knowledge basis. Although the chapters can be read and understood separately, they are intended to be read in succession, as reference will sometimes be made to previous chapters. The organization is as follows: Chapter 2 is devoted to a quantitative and a morphological analysis of urbanization in Europe 2000–2018. Chapter 3 will discuss how the creation of this European urban structure is in part the product of public interventions, focussing especially on the role of spatial planning. Chapter 4 imagines future urbanization pathways using scenarios. Chapter 5 will focus on sustainability, assessing whether developments over the past two decades can be deemed sustainable, what kinds of urban forms are most sustainable, and the extent to which interventions can promote more sustainable development practices. Chapter 6 will draw conclusions for practitioners and theoreticians.