cityscape Public Works: A City That Grows Downward

As an alternative to urban sprawl, urban planners are exploring the potential of subterranean development.

Public Works looks at public space, urban design, and city-building innovations from around the world, and considers what Toronto might learn from them.



Urban areas account for just over 50 per cent of the world’s population today. By 2030, that figure will have increased to 60 per cent. And by 2050, 70 per cent of humanity—an estimated 6.4 billion people—will be crammed into cities around the globe. Urbanization is nothing new; demography has been heading in this direction since the industrial revolution. But as population growth skyrockets, leaders in urban planning are looking for new solutions to the increasing need for space. And while urban growth has traditionally meant sprawling outward and upward, innovators and policy makers in several countries are increasingly interested in the possibilities of subterranean development.

Since its creation in 1996, the Associated Research Centers for Urban Underground Space (ACUUS) has promoted research, discussion, and implementation of underground urban development. At quasi-regular conferences, the NGO brings together global innovators to examine the potential of building infrastructure underneath existing cities, a strategy they see as a way of improving traffic flow, energy efficiency, and land conservation. The next ACUUS conference, to be held this year in Seoul, Korea, will focus on the unique challenges associated with the planning, administration, and design of underground space.

And, in case you were wondering, the conference will not look like this. Or like this. ACUUS’s board of directors is made up largely of academics, and experts in engineering, architecture, city planning, and energy usage.

And they’re not just talking about subways, subways, subways, here. Proponents of underground development envision large-scale building projects such as commercial zones, athletic centres, business parks, pedestrian throughways, highways, and transit systems.

Some urban centres are already putting underground development into practice.

Singapore has built extensive stretches of underground expressways and rapid transit lines. The city state’s government has also committed to updating its “master plan” for urban redevelopment to include major subterranean builds. The feasibility of pedestrian walkways, bicycle lanes, utilities plants, and scientific research facilities is being explored.

As far as building underground is concerned, we here in Canada are ahead of the game. Singapore officials have pointed to RÉSO, a 32-km “Underground City” of corridors beneath downtown Montreal, as an inspiration for their own plans. And, of course, we’ve got PATH here in Toronto, just a shade smaller than RÉSO (not that this is about competition).

Is massive underground development a wholly practical idea? You’ll have to wait for the 2014 ACUUS conference to find out what potential challenges the experts have identified, but “tearing up and tunnelling under large swaths of occupied land,” will likely be one of them. Still, in a city where cyclists, drivers, and pedestrians constantly battle for their own space on the roads, and most people at this time of year would do anything to get from work to the stores to their homes without going outside, maybe expanding our underground presence à la Singapore would be worth a shot.