If you surveyed the entire downtown of Boston, you'd have a hard time finding a worse site for a 1,000-foot skyscraper than the one that's being proposed by Mayor Thomas Menino.
Menino is proposing to sell the site of what is now a hideous parking garage so a developer can replace the garage with a skyscraper 200 feet taller than the John Hancock Tower. The goal, says chief planner Mark Maloney, is to help Boston ''go global and attract new business."
The site is on Winthrop Square. Already, it's hemmed in by two older high-rises on its borders. There are a couple of others you could throw a stick to. We're looking at a possible future downtown of dark windy caverns.
Why would the mayor want to put this building in this place?
Two reasons. First, the city already owns the site. That means the bigger the tower it permits to be built, the more money the city gets by selling the land. In other words, the city thinks of itself as being in the development business and it wants to turn the best profit. But urban design decisions are supposed to be made on some other ground than mere profitability.
Second, the mayor apparently wants to sign the skyline. Although nobody in City Hall will say it, it's whispered that Menino may be in his last term -- when it ends, he'll have served even longer than Kevin White -- and may be looking to leave a physical mark on the city.
I'm not an opponent of skyscrapers. They can be wonderful examples of human aspiration and exuberance. In a city, they're a sort of natural plant species, sprouting wherever they can get purchase, as opposed to the tame formal parterres of a designed garden. They are welcome exactly up to the point where they begin to choke out other forms of life.
In this space a couple of weeks ago, we described Boston's brilliant ''High Spine" concept, which over the years has created a spiky dorsal fin of tall buildings in a ragged line stretching from downtown to Mass. Ave. The Spine has injected much-needed life into the city. High-density building means more people to spill out onto the sidewalks and create street life. It means less need for sprawl in the suburbs.
But the Spine does its job without lowering the quality of life. There's plenty of light and air. When you cram too many skyscrapers into one place, you ruin it for human habitation. Midtown Manhattan is becoming a case in point.
What's wanted is a mix. That's what's so great about Boston. We've found ways to grow tall and dense without destroying our older, smaller buildings. The result is a pleasant jostle of new and old, tall and short, in the same place. Downtown Boston's architecture is like a party where the guests are of all ages, heights, incomes, dress codes, and ethnicities. That's a much more agreeable party than a roomful of tall, pin-striped CEOs.
The other question raised by Menino's idea is whether we're a city governed by laws or governed by whim. The mayor hasn't even mentioned the zoning law. Zoning doesn't allow a building anywhere near this big in this location. That's the way mayors like it. They prefer zoning to be restrictive so nobody can build anything without coming to the mayor, hat in hand, to beg for some form of zoning relief. The mayor, then, is in a position to deal. He can ask for all kinds of amenities -- parks, schools, affordable housing -- in return for allowing an ''illegal" height and density. This is the way you govern a city that doesn't get enough money from taxes. It's acceptable up to a point. But that point shouldn't include a 1,000-foot tower in Winthrop Square.
Let's put the big buildings where they don't block the sun. A good example is the tower, long in the works, on air rights over the tracks at South Station. South Station is a logical site because there's enough space and because the Red Line, Silver Line, Amtrak, and commuter rail all converge here. There are plenty of other developable sites -- on the South Boston waterfront, on air rights over the Turnpike, around North Station, and elsewhere. They can't all accept skyscrapers -- the flight path from Logan prevents that -- but they accept plenty of density. One can imagine the High Spine continuing through South Station onto the South Boston waterfront.
What happens next? The city says it will send out a Request for Proposals in about five weeks. The RFP will ask each potential developer to put together a team, including an architect. It will provide design guidelines intended to create a memorable work of architecture. That may work on the skyline. But what matters about skyscrapers isn't so much how they look on the skyline as what kind of world they shape down at street level, where they face the public. I wouldn't want to be the architect who will have to deal with the inevitable delivery docks, parking ramps, and other messes on this cramped site while still creating a delightful life for pedestrians. Check out the other tall buildings in the neighborhood and you'll see what I mean.
As to the tower's actual purpose, that doesn't seem to enter much into the city's thinking. It may contain, we're told, office space, or residential apartments, or a hotel, in any mix that works in the market when the time comes to build.
Maloney, the director of the Boston Redevelopment Authority, which is Boston's city planning agency, says the mayor asked himself how he could ''add to Boston's global presence." Putting up tall buildings is a recipe for global presence in places like Dubai and Singapore. It's a cliché. We don't need it.
''We want it to be a central beacon," says Maloney. Central beacons can be magnificent, like the Eiffel Tower in Paris or the Duomo in Florence. The problem with thinking of skyscrapers as symbolic beacons is that they're nothing but vertical crates of commercial, rentable space. They lack civic, communal, or spiritual meaning.
I'm not saying Boston should be a museum of the past. There's a conundrum in the life of any city. A city must hoard the great work of the past and, at the same time, promise its citizens a better future. Boston so far has kept that balance pretty well.
Maloney can be a little scary. He says the mayor wants the city to grow. He says 4 million square feet of new space are already permitted. That's about the size of 2 1/2 Hancock towers. Forty million square feet, he says, are planned over the next 30 to 40 years. ''The community work has been done to undergird this growth," he says. Well, maybe.
The question we ought to be debating, perhaps, is whether we want to be America's Florence or its Milan -- a cultural and educational capital, or a business one. Or both? Exactly how much do we want to grow, anyway? And with what kind of growth cells? That's a debate that should be public and vociferous.
Menino's brilliant Crossroads Initiative will soon be underway, with Broad Street as the first example. Key downtown streets will be redesigned with more trees, wider sidewalks, and amenities of all kinds. They will weave the Central Artery land into the city around it. This is the kind of planning we need. Not beacons.
Let's not stuff oversize towers into crowded sites.
Robert Campbell is the Globe's architecture critic. He can be reached at firstname.lastname@example.org.