2020 Workshop

How far in the future is fifteen minutes?

Since the start of the COVID-19 pandemic, architects and designers have been quick to disseminate a range of supposed solutions to the problem of reducing the virus’s spread. The potential usefulness of such proposals is generally questionable, with few garnering much impact beyond an initial flurry of online clicks.¹Kate Wagner, “Coronagrifting: A Design Phenomenon,” McMansion Hell (May 23, 2020). In the more immediate range of spatial tactics so far implemented — the masks, the perspex screens, the travel restrictions — we have seen two main types: measures related to maintaining a prescribed social distance, and measures related to minimizing movement. Like poles on a continuum, these approaches correlate to opposing scales of operation. Distances are enforced in rooms, buildings, and along streets where queues take shape. Movement is reduced across countries, regions, and metropolitan areas. At the intersection of the two — perhaps a point at which design thinking can be most effectively applied — is the neighborhood. One notable response to the pandemic, at this scale, is intensified interest in the concept of the 15-minute city.

A recurring subject across daily periodicals and design-oriented publications in recent months, the 15-minute city is, as an idea, relatively simple: Essential services should be located within a quarter hour’s walk or bike ride from where people live. In essence, each fifteen-minute interval is conceived as a neighborhood in which six basic social functions are made available: living, working, supplying, caring, learning, and enjoying.²Jasmine Reimer, “The 15-minute infrastructure trend that could change public transit as we know it,” HERE (March 24, 2020).

Conceived by Carlos Moreno, an advisor to Paris mayor Anne Hidalgo, and launched as part of her reelection bid in the pre-COVID era of February 2020, the concept draws on a history of neighborhood-based urbanism, from Clarence Perry’s Neighborhood Unit theory, promulgated in the 1920s, to Jane Jacobs’s emphasis, in the 1960s, on walkable urban-village districts.³Kim Willsher, “Paris mayor unveils ’15-minute city’ plan in re-election campaign,” The Guardian (February 7, 2020). Other contemporary initiatives such as Melbourne’s 20-minute neighborhood plan (2017) have emerged with similar concerns for more sustainable urban design.⁴Carolyn Whitzman, “A 20-minute city sounds good, but becoming one is a huge challenge,” The Conversation (June 26, 2020).

The 15-minute city was not imagined as a strategy for redesigning urban areas in the face of potential post-pandemic norms. But it is now being adapted to do just that. Its tactics combine the need for individuals to maintain minimum distances (by providing more public space and safer, more pleasant outdoor environments) with wider reductions in intra-urban movement (through a more even and accessible dispersal of local services).

What is just as key to its application are the goals of equity and mutual dependency. In other words, in the 15-minute city, all neighborhoods must be capable of providing their residents with essential services inside the given area.⁵ Note, however, that 30-minute distances are allowed in suburban areas. See interview with Carlos Moreno: Sarah Elzas, “Can Paris become a ‘15-minute’ city?” RFI (February 28, 2020). No neighborhood can be omitted. The strategy does not work if only some districts apply the model; if the distribution of civic amenities remains concentrated in a small number of centers, inhabitants of other districts will still have to travel long distances by unsustainable means.

While some discussions of the 15-minute city have questioned whether differences between metropolitan areas limit the idea’s universal relevance, less reference appears to have been made to spatial differences within such regions.⁶Patrick Sisson, “How the ‘15-Minute City’ Could Help Post-Pandemic Recovery,” Bloomberg City Lab (July 20, 2020). But if the model only succeeds when all neighborhoods are fifteen-minute neighborhoods, then we must ask: what is the extent of change that will be required in districts now furthest from the ideal?

In this regard, suburbia appears most susceptible. Granted, in the Paris plan, suburban zones are envisioned at 30-minute intervals. Yet, in many places, even this more expansive parameter would be hard to meet. In the U.S., for example, studies have demonstrated that, based on the variety and quantity of amenities available, the vast majority of suburban neighborhoods are “inaccessible” or essentially “unwalkable.”⁷Julia Koschinsky and Emily Talen, “From Sprawl to Walkable: How Far Is That?,” Retrofitting Sprawl: Addressing Seventy Years of Failed Urban Form, ed. Emily Talen (Athens: University of Georgia Press, 2015). Here in Ireland, though the context differs, certain issues remain the same, with low levels of walking and cycling recorded in a number of suburban towns.⁸For example, regarding the suburban towns of Carrigaline and Ballincolig in the Cork Metropolitan Area, research has shown that only three percent of the population walk or cycle to work or school. “Making urban areas more walkable is a step towards fitness: Suburban areas hostile to pedestrians need ‘retrofit’ design to promote walking.” Irish Times (June 25, 2013).

While a lack of existing services is undoubtedly a problem, this at least seems like a lack that suburbia is well equipped to address. Dominated as it is by housing, with ample front and back gardens, the potential for conversion and expansion of residential units to accommodate new uses does not require a great leap in imagination. In many Irish settlements, especially, the house is a type of building block associated with a long tradition of adaptation.

Such transformations may, in the present, be legally unlikely. But they are not without precedent, and are at least physically feasible, with the possibility of change dependent on each homeowner on a plot-by-plot basis.⁹Aron Chang, “Beyond Foreclosure: The Future of Suburban Housing,” Places Journal (September 2011). Clearly, however, there are caps on what can be achieved at this scale. Moreover, any increase in service-provision is of limited value if barriers continue to hamper pedestrian movement. In other words, more fundamental than the issue of building types in suburban areas are restrictions imposed by the design of the street network.

A quick comparative example demonstrates this point. Two Dublin neighborhoods are selected: the Liberties, one of the oldest parts of the city, located near the center; and Lucan, towards the periphery, largely suburbanized during the latter half of the 20th century. Generating two walking-distance maps, each based on a fifteen-minute journey, results in two widely divergent outcomes.¹⁰The comparison was generated via openrouteservice.org, using their route-planning tool. The “generate isochrones” function was selected for walking only. An isochrone is a line drawn on a map connecting points at which an object can arrive in a given time from a single starting point. Differences are particularly notable in terms of shape and extent. In the case of the Liberties, a grid-like network of interconnected streets produces a broadly circular fifteen-minute zone, 3.52 square kilometers in area. By contrast, the form of Lucan’s fifteen-minute perimeter is far less even, with regions to the north and east of the center being largely inaccessible due to a tree-like road layout. The reachable area is correspondingly restricted, covering 1.08 square kilometers, or less than one-third of the accessible area in the Liberties.

Do realities like this make the 15-minute city concept unfeasible? Not necessarily. Rather, they highlight the morphological resistance its implementation would face, an issue generally overlooked in much recent discussion of the concept. It may not be a straightforward or short-term process, but the principles of equity and mutual dependence that underpin the 15-minute city can continue to influence a fairer, safer vision of our urban future.

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About the Author

Michael K. Hayes

Michael K. Hayes is an architect and editor. He is a member of the RIAI and has previously practiced architecture in Dublin, London, and Rotterdam. He is the editor of Architecture Ireland, the journal of the RIAI, and a Design Fellow in Urban Design at the School of Architecture, University College Dublin. Michael has served previously as editor at 2ha, a magazine with particular interest in the suburbs, and at Building Material, the only architectural peer-reviewed annual in Ireland.