Jacobs vs Glaeser: living neighbourhoods and cities that grow

Jane Jacobs and Edward Glaeser are usually cast as opponents, and on one question they are. On almost everything else they are on the same side. Both love cities, the denser and busier the better. Both think cities make people more productive and are kinder to the environment than suburbs or the countryside. Both distrust the planners who wanted to replace messy streets with tidy single-use zones. Their quarrel is over old buildings and height, and it happens to be the quarrel Spanish cities face right now.

Where they agree

Jacobs's The Death and Life of Great American Cities (1961) argued that city districts thrive on diversity, and that diversity needs mixed uses, short blocks, buildings of different ages and enough people. She defended density, drawing a sharp line between many homes on a piece of land and too many people in a home, as the Project for Public Spaces summarises her. Richard Ocejo, reviewing Glaeser's Triumph of the City (2011) in Metropolitics, notes that Glaeser's case for cities is familiar ground for urbanists who start from Jacobs, still the reigning reference in these debates. Glaeser's book argues that cities are the absence of physical space between people and firms, and that this closeness spreads knowledge and creates growth.

A review in Governing in 2011 called them complementary thinkers. That is fair. Both are pro-city, pro-density and anti-sprawl.

Where they split

The split is the third of Jacobs's four conditions. She thought a district needs old buildings because they are cheap: often paid off long ago, they can be let at low rents, and that is where new businesses start. Her line, quoted by the Project for Public Spaces, is that new ideas must use old buildings. She fought to keep the small older buildings of the West Village in New York, and her campaigns helped make preservation a powerful movement.

Glaeser thinks this is where she went seriously wrong, as the Governing review puts it. In a 2010 essay for City Journal, "Preservation Follies", he accepts her point that cities benefit from cheap space. Restricting new building, he argues, is the wrong way to get it. Prices stay low when the stock of buildings grows to meet demand, and when it is frozen, prices rise. He set out the scale of protection in New York: about 1,200 individually landmarked buildings, and about 25,000 more inside 100 historic districts. Greenwich Village became a historic district in 1969, the largest at the time. By his count, nearly 16% of the buildable land in southern Manhattan, leaving out parks, lies in historic districts, where he found less new housing built and residents who had become richer than their neighbours. The essay ends with a line that sums up his side: "No living city's future should become a prisoner to its past."

The irony that runs through all of the reviews is the West Village itself. A working-class neighbourhood when Jacobs lived there, it has long since gentrified and become one of Manhattan's most sought-after areas. For Glaeser, that unaffordability is part of her legacy. The Governing reviewer pushes back that Glaeser is unfair to her on density, pointing out that Jacobs defended Boston's North End at around 275 homes per acre.

Glaeser's remedies are specific. The Princeton Alumni Weekly reports that he would cap the number of buildings each city can protect; once the quota is reached, new construction can go ahead. Ocejo describes his proposal to replace height limits with fees that developers pay for the real costs of extra height, such as lost light and views. In the same interview he says that, given the choice, he sides with people over buildings.

Ocejo's main criticism is useful too. Glaeser's book, he writes, is full of economic measures and says little about how people actually live in their neighbourhoods, which is exactly what Jacobs spent her life watching.

The Spanish version of the quarrel

Spanish cities have both problems at once. Their historic centres are protected by special plans and building catalogues, often with good reason. Around them, much of the city that could take more homes is limited by height caps, parking rules and plot rules set decades ago. Meanwhile the shortage sits in the big metropolitan areas, as our exercise on cheaper housing sets out. The question for Madrid, Barcelona, Valencia or Málaga is what to protect and where to let the city grow.

A radical-centre settlement

There is a well-known city that already tried to answer both of them. Metalocus, writing for Jacobs's centenary, notes that she was called the mother of Vancouverism, the Vancouver approach to planning that the magazine sums up as density done well. That is close to the settlement we would propose.

From the left, from Jacobs, it takes the defence of the street and of the neighbours who make it work: residents keep a real voice, and the things that make a street alive are protected by rule, with active ground floors, doors every few metres, short blocks and mixed uses. From the market-liberal tradition, from Glaeser, it takes the conviction that a successful city must keep adding homes, and that every rule blocking height or replacement has a price paid by the people who would have moved in.

The idea that fits neither camp is the deal between them. Each city draws up a protected list of buildings and ensembles, chosen in public and capped in size, in the spirit of Glaeser's quota. Everything off the list can be replaced and built higher, with developers paying fees for the real harms of height to neighbours, Ocejo's account of Glaeser's idea, and with Jacobs's street-level code applying everywhere. Old buildings survive where they matter most, and the city still grows. Each rule gets the test Glaeser and Jacobs would both accept: does it let more people live in a living neighbourhood?