The Dwelling Complex: I. The Ancillary Unit: B. The strategy of time and change

The ability to evolve is among the most important and underestimated differences between conventional zoning and Transect-based development. The social and economic forces at work on places are always changing. It is better to anticipate change and channel it intelligently than to ignore it and ultimately collapse under its force. Study of sequential images of any evolving historic city reveals this. Dallas, for example, even in its relatively short history, has evolved from what were essentially hovels, to houses, then to brick commercial buildings and on to skyscrapers — all within the same urban grid. The North Dallas suburbs, by contrast, are a collage of housing subdivisions and shopping centers that have thrived, and sometimes died, in the forms in which they were originally built. Various mechanisms militated against their evolution: the rigidity of zoning, the death-grip of the property owners’ associations, and the inflexible finality of the building types. The house, as the most important American building type, will be examined here — particularly in relation to the new urban conception of it as a compound or complex of buildings, often defining private courtyards. Back-buildings and outbuildings, discussed in the last Technical Page, are terms for describing elements of the complex. FOUR TACTICs The simple house is the inaugural condition of urbanism and the first step in the possible successional process. For extension, there are four main techniques, all of which allow its evolution into a denser, more flexible, and more urban complex. The first works on the corner lot house, adding a full second dwelling by taking advantage of the double frontage. This is best done when the original yard is large, or the original house has been consciously designed to accommodate the addition. The cubic structure characteristic of Federal-era design, or the Midwestern four-square, provide good models. A high degree of individuality is possible for both original and added dwelling, since the entrance and parking for each are on different street frontages. The second tactic is to add a story above an alley-served garage. For this to be widely adopted, it is usually sufficient only to make it legal. There is no impact on the urbanism, provided the additional parking can be accommodated off the alley. Care should be taken that access is provided through a side yard so as not to violate the main house’s privacy. The third tactic is to infill side yards. This also can be catalyzed by a simple change in coding eliminating the side setbacks and allowing a greater floor area ratio or lot coverage. Only when the side setback is greater than ten feet is this practicable, but that situation is common enough. The technique, as it increases density, also engages in a comprehensive Transect succession, as freestanding buildings become party-wall ones. The fourth tactic is unusual, politically controversial, but very effective: to build an addition in the front yard. Again, this is accomplished simply by rescinding the setback requirement. It is a better practice than the current convention of adding at the rear yard, which eliminates useful open space. Even a small group of buildings directly on the sidewalk frontage shifts an area decisively up into the next Transect zone. Since front yards in the US are large and ubiquitous, the practice promises to become widespread as the pressure for more compact land use intensifies.