Typology and urbanism: The disposition of types

The most recent Technical Page outlined the idea of typology — an ordered assembly of building types — as a basis for making good urbanism. Any fully developed building type manifests three consistently characteristic aspects; its function,  its configuration, and its disposition. Function is the broad range and mix of activities which may be well-harbored in a building manifesting a given type; it is not the narrow, unreachable-in-practice, mono-use tailoring of Modernist theorization. The type’s configuration is the normative three-dimensional arrangement of spaces which customarily assemble to constitute the type; it denotes both the internal spaces and their relationships. The third aspect, a type’s disposition, is less studied and understood. It is the way the type’s standard configuration is placed on its site with respect to the site’s legal and social bounds. But “is placed” is too passive; disposition is an active aspect, and of paradoxical nature.
Disposition is the most conceptually elusive of the three aspects of a type. Its doubleacting nature is nicely encapsulated in the verb “to cleave.” “Cleaving” can describe both one thing being cut apart and two things sticking together. The disposition of a type describes its cleavings; it includes both the way the type cuts apart or isolates its function and configuration from those of its neighbors, and at the same time the characteristic ways that it adheres well to those neighbors. Disposition is both cohering glue and separating padding, the ways to put buildings closely and intelligently adjacent to one another so that proximity’s advantages are maximized and its disadvantages are minimized.
There are five readily discernible kinds of disposition. They describe the allocation of exterior space between the type’s core building configuration and its property perimeter. In order from more rural to more urban, the first four are Edge Yard, Side Yard, Rear Yard, and Court Yard. The fifth, which may be termed Specialized, has no set relation between configuration and bounding lot edges. (See diagram below from the Lexicon of the New Urbanism).

Divergent type and disposition
Different building types may have the same disposition. For example, Foursquare houses and Center Hall houses are easily told from one another (they have visibly differing configurations), but they are both Edge Yard types, requiring setback space on all sides. Different building types with the same disposition tend to work well adjacent to one another, but it is more than that; similar dispositions of yards not only characterize the rural to urban Transect, they are in fact the strongest factor producing the zones of the Transect.
Edge Yard types have setback space on all sides. Front, sides and rear are determined, with varying degrees of looseness, by the relationships of the core configuration, and the function it contains, to the enfronting street or streets. Front yards are semi-public and visually continuous with adjacent yards; rear yards are semi-private, outbuildings and fences adjusting privacy as needed. Edge Yard types are characteristic of suburban and rural Transect zones.
It is worth noting that types with Edge Yard configurations may change the orientation and emphases of their standard core configurations as lot sizes and adjacencies change. For example, the Foursquare house type on a larger Edge Yard lot often tends to develop into a more three-dimensionally sculptural spiral plan. Conversely, the Center Hall type, which on a larger lot is set broadside to the street and has a very free-form rear service wing, will turn its narrow end to the street and develop a disciplined service tail as Edge Yard lots narrow.
Such changes illustrate a larger tactical point. The typological method of assembling places that satisfactorily balance privacy and proximity is, in practice, supple and flexible. It is perfectly possible to match preset type configurations with actual lots once the nuances of disposition are understood.

Copyright © 2006 Andres Duany, Michael Morrissey, and Patrick Pinnell. Libraries, universities, institutions, and businesses may not circulate, hire, print, use as a teaching aid, or reproduce this article and/or images without the prior written permission of the authors.