Chicago skyline CC image from 1’UP on flickr
Several friends have pointed me to this Atlantic piece by Ed Glaeser on the power of skyscrapers and density in shaping the city, and the role cities play in our economy. Some snippets:
On the micromanagement of zoning codes:
New York slowed its construction of skyscrapers after 1933, and its regulations became ever more complex. Between 1916 and 1960, the city’s original zoning code was amended more than 2,500 times. In 1961, the City Planning Commission passed a new zoning resolution that significantly increased the limits on building. The resulting 420-page code replaced a simple classification of space—business, residential, unrestricted—with a dizzying number of different districts, each of which permitted only a narrow range of activities. There were 13 types of residential district, 12 types of manufacturing district, and no fewer than 41 types of commercial district.
Each type of district narrowly classified the range of permissible activities. Commercial art galleries were forbidden in residential districts but allowed in manufacturing districts, while noncommercial art galleries were forbidden in manufacturing districts but allowed in residential districts. Art-supply stores were forbidden in residential districts and some commercial districts. Parking-space requirements also differed by district. In an R5 district, a hospital was required to have one off-street parking spot for every five beds, but in an R6 district, a hospital had to have one space for every eight beds.
On gentrification, growth, and the hidden costs of height limits and other restrictions:
The relationship between housing supply and affordability isn’t just a matter of economic theory. A great deal of evidence links the supply of space with the cost of real estate. Simply put, the places that are expensive don’t build a lot, and the places that build a lot aren’t expensive. Perhaps a new 40-story building won’t itself house any quirky, less profitable firms, but by providing new space, the building will ease pressure on the rest of the city. Price increases in gentrifying older areas will be muted because of new construction. Growth, not height restrictions and a fixed building stock, keeps space affordable and ensures that poorer people and less profitable firms can stay and help a thriving city remain successful and diverse. Height restrictions do increase light, and preservation does protect history, but we shouldn’t pretend that these benefits come without a cost.
On the inherent dynamism of cities and the shapes of growth:
Great cities are not static—they constantly change, and they take the world along with them. When New York and Chicago and Paris experienced great spurts of creativity and growth, they reshaped themselves to provide new structures that could house new talent and new ideas. Cities can’t force change with new buildings—as the Rust Belt’s experience clearly shows. But if change is already happening, new building can speed the process along.
Yet many of the world’s old and new cities have increasingly arrayed rules that prevent construction that would accommodate higher densities. Sometimes these rules have a good justification, such as preserving truly important works of architecture. Sometimes, they are mindless NIMBYism or a misguided attempt at stopping urban growth. In all cases, restricting construction ties cities to their past and limits the possibilities for their future. If cities can’t build up, then they will build out. If building in a city is frozen, then growth will happen somewhere else.
It’s a fantastic read. I imagine this piece is a prelude for Glaeser’s recently released book, “The Triumph of the City.” I will have to pick up a copy.