Spatiotemporal Model and the Suburban Tissues
The spatiotemporal model suggests that the longer the natural lifespan of a system, the more influence it has on the slower layers in the hierarchy. Using this model to understand the suburban form of Hudson, we see that the most enduring layers, the site and preurban structures, limit the location and expansion of the tissues, while these tissues have little or no effect on the preurban structure. The static tissues and campus tissues respond neatly to this model, fitting comfortably within the preurban structure. In static tissues, the lots and paths form a semirigid matrix upon which certain changes can easily take place and others are constrained. Breaking the bounds of this matrix is an extraordinary event because it is both difficult and unusual. Too many instances of the violation of the matrix can destroy the complex harmony of the static tissue altogether, and in a sense, reformulate it as an elastic tissue or perhaps a different static one. (See examples of Over-the-Rhine in Cincinnati  and Alamo Square. ) For campus tissues, the preurban structure and site is the only real constraint to change.
Changes occur slightly differently in the elastic tissues. In elastic tissues, there is no semirigid matrix to destroy. In most instances, building types are not particularly constrained by the lots, since the lots are not “planned” to accommodate a specific type. Instead, lots have been aggregated from smaller lots (perhaps farms or roadside houses) of no particular dimension. The lot of a strip shopping center may be far larger than the type requires, for example. More usually, a particular building is planned to maximize the use of a randomly sized lot. Another common change is to subdivide a large lot along its road frontage, leaving a larger parcel in the back with road access, and smaller lots in the front, which are developed with smaller buildings. All this leads to a tissue where the buildings are extremely varied in size, type, and configuration. (Adding to this disorder is the current fad of orienting buildings at odd angles to the street.)
Elastic tissues attach themselves like barnacles to the preurban paths since tissue-level streets (e.g., roads in a subdivision) are difficult to coordinate among disparate owners. In a sense the elastic tissues erode the edges of the preurban structure. In the outlying areas of Hudson, the static tissues develop before the elastic tissues, suggesting that the elastic tissues fill in the leftover spaces. In current practice, developers will anticipate the growth of elastic tissues and leave gaps between the planned subdivisions and the preurban paths.
Urban Planning and Spatiotemporal Models
Much planning for suburban areas is done in a vacuum of understanding about how these places are formed. This model of physical growth suggests that there are different planning and design interventions that are appropriate for different layers. In planning for “virgin” territory, for example it would be wise to examine the physical arrangement of existing property boundaries and rural roads, as these are likely to be the checkerboard on which the real estate game is played. Once development begins, the road structure is more or less fixed despite its inadequacy. Intervention at the earliest stages of development of an American suburban region could most productively take the form of rethinking rural networks for new suburban growth.
At the other end of the spectrum, the elastic tissues pose one of the most persistent urban design problems in the modern environment: how to a bring order to areas that are inherently (and, it appears, structurally) disordered. In planning practice, regulatory and urban design techniques have been concentrated on two ends of the “control” spectrum: on the one hand, a minimum set of land use and subdivision standards allows scattered and unfocused development that is widely regarded as ugly; on the other hand, extremely strict planning controls (like new urbanism) allow almost no leeway in any development decision.
Evaluating the problem of elastic tissues in its proper place, that is, looking at the structure of lots and paths at the tissue level, affords no obvious urban design solutions short of massive restructuring. Design guidelines provide a policy appropriate to affect the building layer but do not provide a long-term solution, given the rapid change in buildings. Land use regulation might be effective if physically oriented, but this has not been effectively used for many reasons. The most common, utilitarian solution has been on the cosmetic front, where landscape and streetscape efforts (the object layer) reinforce the edges of the street and thus make visible one of the strongest (and most enduring) underlying forms: the street itself.
This analysis has demonstrated that the suburban form is most strongly related to patterns and shapes that do not normally come to the attention of planners. Modern regulatory process does not address some of the most important and long-lasting layers of the city, while it tends to heavily regulate and intervene in transitory conditions such as land use, building details, and built landscape. I argue that such transitory conditions should be lightly regulated to provide more leeway for growth and change, while the urban framework should be more controlled than current practice allows.