By Deidre Miller…
We know that we need cities to house the world’s billions of human beings. We know that cities have inherent advantages when it comes to sustainability. In cities, people can often get around on foot, by bike and by public transport. On average, urbanites live in less space per person, but in larger buildings that can be heated and cooled more efficiently than detached houses. There is no question that in a world with a human population that will soon top eight billion, cities are important to our future if we want to leave any natural ecosystems at all intact.
But what are the most sustainable urban forms? When she arrived hungry at the three bears’ house, Goldilocks found one bowl of porridge that was too hot, one that was too cold and one that was just right. Is there a “just right” level of urban density that balances comfort, safety and sustainability?
Jane Jacobs Revolutionized City Planning
In 1961, Jane Jacobs wrote her groundbreaking book, The Death and Life of Great American Cities. She was a New Yorker first, then a Torontonian, and most people would agree that she revolutionized city planning in North America and in some ways, around the world. Certainly, she had a huge influence on Toronto’s development and on its success. However, many people have taken some aspects of what she wrote too far, while ignoring others.
Shining Skyscrapers: Too Hot?
Jane Jacobs wrote that urban density can be a good thing and is not necessarily a sign of “blight.” She even believed that low-density cities were doomed to fail and predicted Detroit’s downfall based on its low density. However, Jacobs did not think that more density was always better. In reality, she had many reservations about residential skyscrapers’ vulnerability to crime and lack of easy access to the outdoors.
Some urban enthusiasts have the attitude that more density is always better. However, public transport and other aspects of the infrastructure tend to become less efficient when density is too high, personal space becomes too constricted, the outdoors become less accessible and yes, the hallways and stairwells of high rises become dangerous, blind streets. Some of these problems could be addressed architecturally. High rises themselves could be safer and more comfortable if their public spaces were designed differently. Creating hallways wide enough to be real public spaces, making them more visible, and integrating mixed uses within the same public spaces could turn highrises into something more closely resembling real neighbourhoods. But, would this make economic sense to developers?
Who can deny the beauty of districts full of shining skyscrapers? They’re a triumph of human ingenuity. However, with circulation driven by elevators and the necessity of 24-hour lighting in public areas, these buildings are very dependent on technology to function and are not terribly energy efficient.
“Country Living” in the Suburbs: Too Cold?
After World War II ended, North America and, to a lesser extent, Europe, saw the growth of low-density suburban neighbourhoods. They sprang up based partly on an idealized view of country life and partly out of a desire for safety, isolation and control. North American-style suburbs allow nuclear families to live in detached houses on sizeable lots in purely residential neighbourhoods with little street life and no economic diversity.
In most of these neighbourhoods, it’s necessary to use a car in order to reach workplaces, shops, restaurants, churches, schools, parks and disturbingly, pubs. People who argue that suburbs can be sustainable point out it’s possible to grow food and keep small animals in suburban yards. In reality, neighbourhood standards for the appearance of the properties tend to exclude small scale agriculture. In any case, it’s difficult to see how the lack of walkability, accessible economic life and public transport in any way adds up to a sustainable way of life, with or without a little bit of home food production, especially when farms are usually located only a few miles further out.
Suburban sprawl is only possible when and where there’s cheap land and cheap fuel, and it will only continue to be practical while family cars are common and fuel is relatively cheap.
Human Scale and Mixed Use: Just Right?
Is there, as Jane Jacobs suggests, an optimum level of urban density that offers walkability and cost-effective public transport while giving city residents easy access to the outdoors and green spaces?
When it comes to urban density, land values dictate that there will always be dense housing forms like residential skyscrapers in areas where property values are very high. However, there may be a “just right” level of urban density that balances comfort, safety and sustainability. Was Jane Jacobs right? She loved New York’s brownstones: multi-residential three to five story walk-up apartments and townhouses.
Medium density urban areas can be found around the world, including in large swaths of Toronto and Montreal. Most European cities are predominantly medium density. Many older medium-density neighbourhoods survived the twentieth century’s overactive urban planning and “urban renewal,” partly because the residents showed no interest in abandoning their neighbourhoods for lower density suburbs or higher density skyscrapers, and were indeed willing to renovate at their own expense and fight for their neighbourhoods’ survival. This wasn’t just because the buildings were nice looking. It’s because the neighbourhoods are well structured for both efficiency and livability. They’re both affordable and comfortable.
Thanks partly to Jane Jacob’s influence on Canadian urban planning and architecture, mixed use, medium density urban neighborhoods have a secure future in Canadian cities. The three projects below are typical of some of the new, medium density urban architecture coming out of Canada, particularly Montreal and Toronto, since the turn of the 21st century.
Deidre Miller is an engineer with an architecture degree who has lived in the U.S., Canada and the U.K. and worked in building design, evaluation and regulation.