The Death and Life of Great American Cities

This ubiquitous principle is the need of cities for a most intricate and close-grained diversity of uses that give each other constant mutual support, both economically and socially. The components of this diversity can differ enormously, but they must supplement each other in certain concrete ways. I think that unsuccessful city areas are areas wh

If secondary diversity flourishes sufficiently and contains enough that is unusual or unique, it seemingly can and does become, in its accumulation, a primary use itself. People come specifically for it. This is what happens in good shopping districts or even, to a humble extent, on Hudson Street. I do not wish to minimize this occurrence; it is vi

Secondary diversity is a name for the enterprises that grow in response to the presence of primary uses, to serve the people the primary uses draw. If this secondary diversity serves single primary uses, no matter what the type of use, it is innately inefficient. Serving mixed primary uses, it can be innately efficient and—if the other three condit

No neighborhood or district, no matter how well established, prestigious or well heeled, and no matter how intensely populated for one purpose, can flout the necessity for spreading people through time of day without frustrating its potential for generating diversity. Furthermore, a neighborhood or district perfectly calculated, it seems, to fill o

Effectiveness means, first, that the people using the streets at different times must actually use the same streets. If their paths are separated from one another’s, or buffered from one another’s, there is no mixture in reality. In terms of city-street economics, mutual support among differences is then a fiction, or something to be seen merely as

But population size is vital because it represents, if most of the time only by implication, votes. There are only two ultimate public powers in shaping and running American cities: votes and control of the money. To sound nicer, we may call these “public opinion” and “disbursement of funds,”

hundreds of ordinary enterprises, necessary to the safety and public life of streets and neighborhoods, and appreciated for their convenience and personal quality, can make out successfully in old buildings, but are inexorably slain by the high overhead of new construction. As for really new ideas of any kind—no matter how ultimately profitable or

The reason Greenwich Village can reconcile such high densities with such great variety is that a high proportion of the land which is devoted to residences (called net residential acres) is covered with buildings. Relatively little is left open and unbuilt upon. In most parts, the buildings cover the residential land at averages estimated as rangin

Among all the various kinds of buildings (old or new) in a city, some kinds are always less efficient than others in adding dwellings to the land. A three-story building will get fewer dwellings onto a given number of square feet of land than a five-story building; a five-story building, fewer than a ten-story building. If you want to go up far eno