Isegoria

Building regulations in the developed world, especially the United States, have made cities far more susceptible to heat, Connor Harris explains:

And this is just one instance of a broader lesson: regulations can hurt the environment just as easily, or even perhaps more easily, than they can help.

I live in Houston, the most notoriously hot and humid large city in the United States, in an intensively redeveloped prewar residential neighborhood that comprises mostly mid-rise apartment blocks and three-story townhouses. Even Houston’s summer heat is quite comfortable in most circumstances. I have never felt overheated while eating lunch outdoors on a shaded patio, for example, or even after mid-afternoon bicycle trips along local roads or walks along shaded sidewalks and park trails.

Houston heat is made intolerable by the city’s vast quantity of heat-absorbing asphalt and the frequent lack of shade. I frequent a few restaurants a short distance from my apartment, in strip malls off of a busy, six-lane arterial road. The walk from my apartment to the restaurant, along an unshaded sidewalk between the road on one side and the parking lots of the strip malls on the other, is far more uncomfortable than even exercise in the shade at the same temperature. Even a short one-minute walk through a big-box store’s parking lot can be almost intolerable and make the air conditioning inside feel almost life-saving. More rigorous research confirms that large parking lots contribute powerfully to the urban heat island effect. It’s no wonder that anyone whose experience of the Texas outdoors involves mostly walking between cars and commercial buildings would find the heat oppressive.

These aspects of Houston’s built environment owe less to the workings of the free market than to a set of market-distorting land-use regulations that sacrifice heat resilience, while also wasting large amounts of valuable land, in the name of giving motorists maximum possible convenience. In these respects, Houston’s land-use regulations are perfectly ordinary. Most prominent are the massive requirements for off-street parking spaces for almost all types of development outside a few downtown areas. In Houston, even studio apartments, seldom occupied by more than one person, require 1.25 parking spaces. Any commercial development requires far more parking space. Supermarkets, for example, require five parking spots per 1,000 square feet of floor area. Bars and restaurants, depending on classification, can require up to 14. A typical parking spot takes up about 300 square feet of space, so such establishments could need four times the amount of land for parking lots as for their building itself. Many commercial parking lots often sit mostly empty.

Other common aspects of American land-use codes, such as setbacks and traffic engineering standards, also make heat in American cities harder to bear. Old cities in hot regions such as Latin America and the Middle East typically have buildings (which often incorporate colonnade walkways) set close to the street to provide shade for pedestrians—an eminently sensible design specifically prohibited by most American zoning codes, which enforce a suburban appearance on residential neighborhoods by requiring “front setbacks,” or wide margins of land along the street that cannot be built on. Builders typically pave over large amounts of this setback land to provide driveways much longer than they would have to be without setbacks, adding yet more hot asphalt into cities.

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Traffic-engineering standards also contribute to overheated cities. Houston, for instance, mandates street widths of at least 50 feet on local roads in new subdivisions—more than four times the standard 12-foot width of an interstate highway lane. This gives enough room for cars to pass one another at speed with one lane of parking on each side of the road, a massive waste of land and asphalt in residential areas with plentiful off-street parking where, even at rush hour, local roads will see at most a few cars per minute. It’s common traffic-engineering practice, as well, to maintain the sides of major roads as “clear zones” free from trees and other fixed obstacles, in order to limit the damage to cars that run off the side of the road. This practice eliminates shade while providing only doubtful safety benefits.

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