Does dense equal sustainable?

density Illustration by Julianna Brion
Illustration by Julianna Brion

It has become accepted wisdom that density is a good thing, as part of the notion that cities should grow, adapt and change if they are to become more sustainable, create jobs and remain economic engines.

But not all density is created equal, and there is such thing as too much density. That’s where many academic planning journals and right-wing think tanks start to cross the line. Many complain of too many restrictions that are keeping high-rise condos and business towers from blooming like weeds in a vegetable garden.

A series of recently published books have also perpetuated this view, some taking it to the extreme. Take the following excerpt:

“The environmental challenge we face, at the current stage of our assault on the world’s non-renewable resources, is not how to make our teeming cities more like the pristine countryside. The true challenge is how to make other settled places more like Manhattan.”

That’s the pitch from The New Yorker writer David Owen, with his book Green Metropolis: Why Living Smaller, Living Closer, and Driving Less are the Keys to Sustainability. He noted that New Yorkers use less energy per capita than anybody else in the U.S., so therefore we should all live like New Yorkers. After all, they all live in apartments with shared walls and mostly walk and take transit, saving a huge amount of energy compared to car-driving suburbanites. Forget light bulbs and insulation, Owen argues, what matters is density. It’s a line of reasoning picked up by every real estate developer building leaky glass condos.

For economist Edward Glaeser, nothing is sacred. He’s the writer of Triumph of the City: How Our Greatest Invention Makes Us Richer, Smarter, Greener, Healthier, and Happier. If he had his way, he would demolish New York’s Greenwich Village and build 40-storey towers everywhere to increase density and the supply of housing. He is an economist, not a sentimentalist, and notes there is a price paid whenever we stand in the way of development: “Preservation isn’t always wrong – there is much worth saving in our cities – but it always comes at a cost.”

Alex Steffen, in his book Carbon Zero: Imagining Cities That Can Save the Planet, makes a strong case that the only way we are going to dig ourselves out of the mess we are in is to live in sustainable cities.

“Americans, Canadians and Australians, in particular, sail now on a collision course with planetary realities. Our sprawling suburbs and low-density cities depend on abundant resources, cheap oil, and low costs for pollution, none of which the future holds.”

But he, too, claims that to keep cities affordable, “we need policies that result in thousands, sometimes even tens of thousands, of homes built each year. This is basic economics.” He also objects to NIMBYs who are trying to save their neighbourhoods as standing in the way of saving the world.

The problem with all of these free marketeers is that at some point it becomes counterproductive – densities can get too high. Upgrading transit to service Manhattan densities is extraordinarily expensive; the new 2nd Avenue subway is costing $1.7 billion per kilometre, where a dedicated streetcar line like that on Toronto’s St. Clair Avenue cost $37 million per kilometre, one-46th the cost.

Ken Greenberg tells of another way, where one doesn’t have to throw legendary urbanist Jane Jacobs under the bus. In Walking Home: The Life and Lessons of a City Builder, he describes the virtues of a greener, denser, but still Jacobsean place where there is “a strong, deep culture of the city with a widely shared web of relationships, a deep bench of committed city champions and a long collective memory.”

What might life in our cities look like if we aggressively filled in the obsolescent rail yards and port lands, cleaned and remediated their polluted soils and built denser, more walkable neighbourhoods? Our living spaces might be smaller, but that would be compensated by a greater variety of public spaces, amenities and necessities close to hand, so we will likely spend less time in our own private spaces anyway.

Density is important and necessary to make a city work. But it can be too tall, too dense, too spiky. Too much of it can kill a neighbourhood or a city. As that great urban theorist Yogi Berra said, when describing a St. Louis restaurant he once frequented, “Nobody goes there anymore. It’s too crowded.”

Latest from Built Environment

current issue