Urban peripheries and the 15-Minutes City. A comparative study of planning policies aiming at applying the concept of proximity to suburban and semi-dense areas.

Abstract

Since its introduction in 2015 at COP21 in Paris the 15-Minutes City (ville du quart d’heure) has been widely discussed and has become quite popular even outside the academic and professional debate. Since then its promoter, Carlos Moreno, and his team of Chaire ETI at Université Paris 1 Panthéon Sorbonne have further elaborated the concept.

Moreno conceived the concept as a response to the key climate and health issues imposed on cities and territories by the multiple crises of our time such as climate change or global pandemics (Chaire ETI, 2020, p. 3). Consequently, the concept has been adopted by the “C40 Cities” network as the keystone for their vision for ecological, just and human-centred urban design in the 21^st century (Moreno, 2020, p. 118). Furthermore, in the second white book of Chaire ETI several pioneer cities are listed, such as Ottawa, Melbourne, Portland, Barcelona, Milano, Nantes and Mulhouse (Chaire ETI, 2020, pp. 20-45).

It is striking that the majority of these so-called pioneer cities, apart from Nantes and Mulhouse, are metropolises of national or even international importance which have a very compact and mixed-use urban structure that might fulfil Moreno’s criterion of proximity, already to a large extent. However, Roger Keil and Wu Fulong point out that “urbanization in the twenty-first century is increasingly occurring in the peripheral areas outside the city” (Wu and Keil, 2022, p. 11) for which Thomas Sieverts coined the term “Zwischenstadt” (Sieverts, 2012). In Germany for example approximately 62 to 75 percent of the population already live in these urban peripheries (Bremer 2022, p. 33). Consequently, developing guiding principles for the transformation of these Zwischenstadt areas in order to decrease consumption of space, sealing of surface and mobility-related CO₂ emissions can play an important role for the sustainable transformation of the built environment.

That is why Moreno suggests to extend their concept of the 15-Minutes City to semi dense or less dense areas and calls that adaptation the 30-Minutes Territory which could provide a new territorial framework (Moreno 2020: 127f.). A first methodological approach on how to apply the criterion of proximity on peripheral areas is presented as part of the research project “Portes de Paris” carried out by Chaire ETI and published in its first white book (Chaire ETI, 2019). It appears that this could be a fruitful approach as Sieverts already pointed out, that walkability plays a key role in transforming urban peripheries (Sieverts, 2012, p. 39).

In my study I will examine the question if and how different planning policies apply the idea of the 15-Minutes City or the 30-Minutes Territory on Zwischenstadt-like urban peripheries by comparing the official documents of different municipalities which are claimed to being based on the concept of proximity and the 15-Minute city, e.g. Ottawa’s “5 big moves” (Chaire ETI 2020: 21), Melbourne’s “Plan 2017-2050” (Chaire ETI, 2020, p. 24) and Portland’s “20-minute neighbourhood” (Chaire ETI, 2020, p. 29). The goal of the study is  first to assess if the documents address urban peripheries at all and if yes what significance is given to them. Second, it will be analysed on which aspects of the 15-Minute city, e.g. proximity, density, mixed-use or ubiquity, the individual policies focus on and, third, by which means and strategies they intend to reach their goals, e.g. increasing walkability or bikeability, increasing building density, establishing mixed-use by the implementation of new typologies or by adaptive re-use of existing building structures. It is expected that the results of the study can contribute to answering the question whether and how the 15-Minutes city concept can be applied to urban peripheries.