"We need to broaden the concept of the 15-minute city"

The 15-minute city vision has been widely adopted internationally. But new research shows that the vision risks missing the mark if it only aims to reduce emissions.

School, work, shops, leisure and green spaces - all within easy reach. The idea behind the 15-minute city is that the most important functions of everyday life should be within walking or cycling distance, with the aim of reducing car dependency and emissions in particular.

There are challenges with the 15-minute city that the debate and research have not previously taken into account. A new study at the University of Gävle highlights social and ecological factors that need to be included for the 15-minute vision to work.

"Risk that we build vulnerable cities"

"The idea of the vision is good, but we need to think in a broader perspective. Otherwise, there is a risk that we will build cities that are both ecologically and socially vulnerable," says Åsa Gren, senior lecturer in environmental science at the University of Gävle.

In a new scientific article, Åsa Gren and Meta Berghauser Pont, Professor of Urban Planning at Chalmers University of Technology, show that the 15-minute city is not enough as a solution if you only focus on the local. For the vision to work in practice, cities or neighborhoods need to be planned in several layers. The researchers highlight three examples:

• Cloudbursts and floods: Small, local solutions like green roofs help - but not enough. Protecting cities from heavy rainfall also requires planning from a large-scale runoff perspective.
• Bringing people together: If each neighborhood becomes its own little 'island', there is a risk that people will never meet across borders. To reduce segregation, public spaces need to be not only accessible locally, but also connected to the wider city network so that more people can move between different areas.
• Food and pollination: Urban green spaces can help secure our food supply, but they need to provide habitat for pollinators like bees. However, for this to work in the long term, green spaces need to be connected across the city.

Can become isolated

Neighborhoods that follow the 15-minute idea risk becoming socially isolated, a bit like a gated community, but without visible walls.

"If you only move around in your own bubble, you run the risk of only meeting others who look and think like you. This often leads to poor integration," says Åsa Gren.

The researchers warn that too narrow an application of the 15-minute concept can lead to so-called "scale mismatch", where what is thought to work locally does not deliver because the links to the larger context are missed.

"This is not about abandoning the 15-minute idea, but about strengthening it. It needs to be linked to ecological networks, social inclusion and larger functional connections in the city," says Gren.