Making room for urban expansion matters because it ensures a supply of developable land that is ample enough to keep housing affordable for the urban poor. It also matters because it allows the city to guide development rather than follow it. By leading rather than following development, cities can greatly reduce the cost of providing infrastructure and public open spaces and ensure that all urban residents have access. In short, cities that make room will be more equitable, more efficient, more livable, and more sustainable.

In rapidly growing cities, making room for urban expansion entails four key steps.

• The first step involves making realistic projections, both about the amount of land that the growing urban population will require and where the physical expansion of the city is likely to take place.
• Second, cities must work with regional and national officials to ensure that they obtain jurisdiction over the projected area of expansion.
• The third and fourth steps involve basic urban planning in the area of expansion. The city will have to establish the rights of way for a network of arterial roads— roads that will one day carry public transit and private traffic as well as infrastructure such as water mains, sewers, storm drains, and telecommunications networks.
• Finally, the city will have to identify public open spaces, including environmentally sensitive areas, and work to protect them in the face of urban development.

To-date, we have two country-based initiatives at advanced stages: one in partnership with Cities Alliance that is focused on four cities in Ethiopia, and another in partnership with CAF Development Bank of Latin America focused on five cities in Colombia. In both countries, a number of cities have finalized their plans for the infrastructure grid areas, and have begun to secure the rights-of way in their expansion areas for a grid of 30-meter-wide arterial roads, spaced one-kilometer apart. What’s more, national authorities in both countries are now working with us to expand the initiative to more of their fast-growing cities.