David Owen, author of the Green Metropolis, writes:
He and others, including Edward Glaeser, Ryan Avent and Matt Yglesias think that cities have to be denser and taller to allow for economic growth, to preserve the environment and to reduce energy consumption. Amy O'Leary recently wrote Everybody Inhale How Many People Can Manhattan Hold? and writes about Glaeser:
The environmental challenge we face, at the current stage of our assault on the world's non-renewable resources, is not how to make our teeming cities more like the pristine countryside. The true challenge is how to make other settled places more like Manhattan.
He makes an argument — which many consider persuasive — that dense places are uniformly better and more interesting than emptier ones, and that they should be allowed to develop unfettered, even if it means building towers where brownstones once stood.
I do not consider the argument persuasive for a number of reasons, and was invited on to WNPR's Where We Live to discuss this. I never got to speak with Owen, who was on before me, but did get to debate the point with Amy O'Leary. You can listen here.
Glaeser and Avent call for removal of restrictions on greater density, suggesting that it will lower housing costs, and will allow for more people, more innovation and more wealth creation.
But There is another way to wind up with bad places and poorer people: Build too much and too tall in an age of climate change and Peak Oil. I have no issue with Ryan's position that greater density leads to greater productivity; Tim de Chant has shown that it has been this way for millennia . I am a big fan of density, and of walkable cities and compact living. But I think there is an appropriate density, a Goldilocks density that is not too low, not too high, but just right. You also have to look at the larger picture, beyond the municipal borders.
While those extremely dense cities like Hong Kong and New York use less energy per capita, they still use a hell of a lot of energy and the back of house required to support it, the food supplies, the water and electricity infrastructure, are all huge and not particularly efficient. William Rees of the University of British Columbia put it better in Scientific American:
Urban designers must rethink cities as complete ecosystems. The most resilient option might be a bioregional city-state in which a densely built-up core is surrounded by supportive systems. Without becoming isolationist, such bioregions would produce much of their own food, fiber and water and recycle their waste.
And of course, there is always James Howard Kunstler.
While I'd agree that tight, dense, and walkable urbanism is crucial for our future happiness, it's a tragic error to suppose that stacking people in skyscrapers is necessary to achieve this…. The infatuation with skyscrapers is just another facet of the technological grandiosity that pervades American culture these days--the dangerous idea that we are unbounded by limits.
Perhaps a city can be too big and too dense, to the point that it is no longer resilient or, as James Russell calls it, agile. He thinks, as I do, that our planning and urban design went awry when cheap electricity and fossil fuels made it so easy to do anything we wanted. But when they start running out, we start having problems.
High buildings need a constant supply of energy to keep the water flowing and the elevators running. The service and elevator cores get bigger and take up a higher proportion of the floor area. Repair and maintenance costs at the end of the service life of components like the cladding and the mechanical systems are absolutely huge. Their glass skins have an R value of about two, and their window openings so small that they are being heated and cooled year round, even on the nicest days. Our energy efficiency and our building density is less than it was a hundred years ago, when there were three hundred people packed into an acre of downtown New York in low rise walkups.
I am not an economist; perhaps Glaeser and Avent are right that unleashing free market development forces will lead to dramatic increases in density and lower housing costs. As a former real estate developer, I have found that doing so leads to shortages of trades and construction materials, increased construction costs, followed by oversupply and market collapse. It also leads to crappy cities with no charm.
I think I am going to stop writing about what economists have to say about building our cities and start looking at what urban designers have to say. I think they have a better chance of getting it right.