Toronto city planners may not know what they like, but to the rest of us the answer is obvious: glass towers.

You don’t have to go far in this city to come across the results of the planning department’s love affair with the now ubiquitous see-through highrise. There are dozens of examples of architectural transparency, one barely distinguishable from the other.

Indeed, it has reached the point where any new tower that isn’t clad in glass stands out from the crowd, and for Toronto planners, there’s no sin worse than standing out.

At the same time, it’s not hard to understand why planners and developers have grown to love the glass boxes — they’re cheap, buyers love them and any number of precedents has been set for the municipal bureaucracy. So they’re safe.

Despite concerns about the sustainability of the glass-walled condo and the monotony they have brought to the Toronto skyline, these are not issues that concern city planners. That’s someone else’s department.

For planners, the main thing is to ensure that everything fits in — in other words, that nothing stands out. As long as a building isn’t too tall, too dense, or too good, the department is happy to give its approval.

And for the most part, it’s a good thing to insist that buildings fit in. Too many soloists in the choir leads to cacophony. But as is always the case, rules were meant to be broken. Some buildings are important enough that they should stand out — City Hall, museums, galleries, concert halls, train stations among them.

Many cities also make exceptions for ordinary buildings designed by extraordinary architects. The Turning Torso condo tower in Malmo, Sweden, looms over its neighbours. But it was intended to be a landmark, complete with souvenir shop across the road. Designed by Spanish architect Santiago Calatrava, it is the tallest building in the country.

But in Toronto, a city terrified of change and, therefore, awash in NIMBYism, planners are always nervous. Too frightened to be imaginative, let alone bold, they resort to a sort of checklist approach to approval. As the endless glass towers make clear, the result is a city of sameness and desirable only because it offends the least number of people, is most easily defended and keeps planners from having to justify their actions.

Whether the planning department actually believes in the mediocrity it has unleashed on Toronto is beside the point; banality is the inevitable result of its planning-by-default approach.

Typically, we blame developers. And god knows, they have much to answer for. But it’s time we take a closer look at their handmaids at City Hall: the planners. They are the real experts.

Architecture critic Christopher Hume moves beyond the singular condo to look at residential design in Toronto. chume@thestar.ca