That's the thing about time: it only moves forward. So does the city - and sometimes not very elegantly. No amount of collective good taste, for example, will ever remove the mid-century concrete insults that dot the landscape.
And the fact that much of this brutalist form - the Gardiner Expressway, 50s and 60s suburban apartment blocks - is also unsustainable means our immediate instinct is likely to be to tear them down.
How sustainable would that be, though? It would be interesting to see how much rubble could be recycled. The foundation of a section of New York's FDR Drive, for instance, is mostly rubble from bombed British buildings carried as ballast in wartime ships.
But much of our Modernist superstructure would be hard to simply take apart; and a war against deprecated architecture would turn into a war against heritage - and the poor.
Even decades ago, urban sprawl was on the minds of planners. Back then, Steeles was the greenbelt. The strategy to keep it that way was construction of "satellite" towns (such as the centrally planned and developed Don Mills) and the high-rises still bringing a bit of Siberia to the GTA.
"Driving down the 401 recently, I thought, 'We really do live in Moscow,'" says Graeme Stewart, principal at E.R.A. Architects. "The image we try to give is a downtown with streetcars, when that's a really small part of the city."
By Stewart's reckoning, Toronto has the second-highest number of high-rises in North America, next to NYC. Most are concrete towers in the north end. In his time, 1960s smart-building guru Buckminster Fuller lauded us for it. They were cachet destinations then, symbols of sophisticated urban living. Now those neighbourhoods stand neglected.
The American experience, opines Stewart, associates tower blocks with slums. But more rational planning has prevailed elsewhere over "tower in the park" ideas. "If we look to Europe," he tells me, "these have often been quite well integrated."
This is the point he brought to City Hall May 28, presenting to the executive a strategy for rehabilitating suburban apartment behemoths into benign ecological sites. As it turns out, the towers' simple, standard and sturdy form would make them easy to retrofit by giving them a second skin of thermal cladding, under which infrastructure for stormwater and waste management, geothermal energy and district heating could run.
"This is the middle of the GTA, and this could be as sustainable as it gets," said Stewart. "These buildings could be completely off the grid." But their potential for self-sustenance goes beyond energy.
By overlaying a map of high-rise colonies with data from the TTC and the United Way's Poverty By Postal Code study, Stewart illustrated the high correlation between post-war tower blocks and poverty, and a negative correlation with transit connectivity. What were once exclusive places are now destinations for the excluded.
But those dense buildings in North York, Etobicoke and Scarborough have great potential; what often makes them wastelands - the flat expanses surrounding them - could make them a new model of urbanism.
Inspired by projects in Europe, Stewart calls for the city to relax the zoning of those areas for infill development of shops, community centres, even agriculture and animal husbandry - essentially reviving and rejuvenating the satellite town model as a means not only to green the areas but also to allow them cultural and economic expression.
"Currently, all of this is prohibited," he said. "They're classified as 'stable neighbourhoods.' It's kind of funny. They treat these neighbourhoods as they would Forest Hill."
Stewart stressed that if the zoning is relaxed, it will have to be with strings attached: developers creating this new retail/mixed infill would need to funnel a certain amount of the revenue directly back into the towers and sustainable community projects. One that leaps to mind is the Transit City light rail plan proposed in part to run, among other routes, along Finch, Sheppard and Jane, right through or near most of the larger tower colonies.
"We'll have to move from market-led, reactive city building to city-led, proactive city building," said Planning Committee chair Brian Ashton. "It won't just happen because it's a great idea."
First step? A real budget for the planning department. And a willingness on the part of the city to really poke its nose into development; to make it mandatory, for instance, that commercial development be prioritized, and that it be accessible, in size and price, to local, independent merchants.
Developers will bemoan their lost profits. And in response, planners will have to play the world's smallest city-planning violin.
Could the discussion of the burbs lay the groundwork for the future rehabilitation of downtown towers such as St. James Town or Parkdale's West Lodge, or the revamp of low-density suburbs, I wonder. Stewart thinks so.
And it's not long before the mind wanders to, say, embattled cousin the Gardiner. I know I'm supposed to see it as a "barrier to the waterfront," but personally I love the texture, the sense of levels, it gives to the city - and I can't help imagining what an amazing bike highway it would make.
Thinking of those towers as gifts inspires hope for a great challenge: how we will adapt to the concrete manifestations of poor choices made by generations past, like someone in later life adapting to injuries incurred in youthful folly. It's an experiment in accommodation with time - in how we as a city can learn to live joyfully with regret.