In his eyes, skyscrapers are the height of green living. But as architect Michael Mehaffy and others have pointed out, tall buildings can be less energy-efficient than shorter ones. In cities lacking the intense development pressure of a New York or Hong Kong – i.e., most other U.S. cities – one skyscraper can suck up a disproportionate chunk of the existing market, leading to the odd sight of tall towers surrounded by surface parking lots – not your greenest landscape.
Regarding the energy efficiency of skyscrapers, she doesn’t link to any one claim in particular so I’m not sure what exactly Michael Mehaffy’s argument is, but I suspect that it doesn’t account for transportation energy use. Tall buildings (4+ stories), when built in large numbers, transfer a lot of energy spent on transit from horizontal modes (cars, rail, your feet, buses) to the one relatively energy efficient vertical mode: the elevator.
As for skyscrapers surrounded by a sea of parking, when does this actually happen? I can think of two instances: public housing projects, and places with high minimum parking requirements. Neither of these are really the fault of skyscrapers.
Mary also makes some similar, more reasonable, arguments against Glaeser’s skyscraper obsession – as one blogger who I can’t remember or find right now pointed out a while ago [edit: It was Charlie at Old Urbanist], skyscrapers make up a pretty small portion of NYC’s total number of units. But then again, skyscrapers are also the most regulated-against form, so I’m not sure how much we can learn from revealed preferences.
I don’t have any one fact in particular to back this up, but I suspect that the demand for living in high-rises (say, 10+ stories) is actually a lot higher than a lot of urbanists suspect. New Urbanists idolize the three- and four-story towns of yore (James Kunstler famously announced the death of skyscrapers after 9/11), but I see skyscrapers sprouting essentially wherever they’re allowed.
When Mary says that most US cities other than New York couldn’t support them, she’s only right in as far as you consider Woodland Mills a city. There are many other large and mid-sized cities, though, that I think could definitely support a few dozen more skyscrapers. In the Northeast alone, the feeding frenzy in Northern Virginia demonstrates that the Washington region would obviously sprout tons of towers if they were allowed. But even outside of the red hot DC market, I think it’s safe to say that there’s demand for quite a few more high-rises in many neighborhoods in Philadelphia, Boston, North Jersey, Queens, and Brooklyn. Hell, I’m sure even some places that are very car-oriented nowadays but have good transit access – mainly wealthy suburbs like the Main Line outside of Philadelphia and Long Island and Westchester in the New York metro area – would see a few towers go up if they let them.
I have a feeling that a lot of urbanists downplay skyscrapers in order to appear politically palatable to places that are hesitant even about mid-rise New Urbanist-style development, but sometimes I think they get a little carried away. This sort of anti-skyscraper sentiment, when taken to the extreme as it is in DC, can have very real consequences. It may have forced the city to be a bit more proactive in other deregulatory moves, like parking minimums (as I understand it, DC’s plan will be the most radical off-street parking deregulation in the country). But unless the Height Act is repealed and a significant amount of skyscrapers are allowed, I worry that the city’s dizzyingly high rents will never fall.