Incremental Planning

We often find ourselves wandering through the older parts of cities and these places are generally walkable, diverse, varied, and engaging. And they seem always to elicit the same question—why can’t we make places like this today? The one consistent characteristic common to all these areas is that they were developed incrementally, over time, evolving with each addition. The additions can vary in size and frequency and be more or less consecutive, but the basic idea is that city growth occurs through the completion of small projects. Historically this is the process of subdividing land. The increment of development—the subdivided parcel—was small. This seemingly arbitrary growth was true regardless of a centrally derived town plan or a city that grew by planning on the margins. In many cases, the idea of incremental growth is referred to as an organic progression. While wandering through Marrakech the mind contemplates the irregular pattern of the inviting “organic” streets. This perception is a misapprehension in which organic composition comprises forms that are not regular or orthogonal, thereby clouding the actual underlying characteristic of the city’s development. That is, the seeming randomness of the city’s development pattern isn’t the result of its level of incremental development. Instead, it is a reflection of the type of incremental development. It is a city developed in the absence of a projected, planned public framework. Whether a city possesses a proposed public framework as with New York’s Commissioner’s Plan, or it does not, as in the case of Chinon’s historic center, neither is indicative of the level of incremental development intrinsic to expansion. New York’s structure is not perceived as incremental by virtue of the projected plan with its generally straight lines and right angles. And it is certainly not commonly referred to as organic. However, development happened in a primarily incremental manner, and in many ways, organically, although operationally organic, not compositionally organic. The city grew through a large number of small changes. New York is a rational, gridiron plan. Paris is a series of generally straight streets that aren’t parallel. London is a series of not-so-straight streets that are rarely parallel. In the compositional sense of the word, organic somehow equals irregularity of form. By this assessment, it is probably accurate to say New York is the least and London the most organic of the three examples. But in the operational sense of the word, organic represents an incremental process of development over time, with many small projects developed individually. Today, almost all planning starts with a projection. This is like mapping out potential future uses with precise planning zones across areas to be developed and includes new cities, redevelopment areas, and pretty much every development, regardless of scale. All planning starts with and is supported by this legal framework and conventions that make changing the process virtually impossible.