Suburban Nation - Andres Duany [46]
Windsor: small lots that offer privacy as well as community
There is one other crippling misunderstanding that prevails in the development industry regarding traditional versus conventional design. Some developers who are unschooled in the details argue that traditional neighborhoods are more expensive to build than conventional subdivisions—“Who’s going to pay for the alleys?” they ask. That gripe is easy to refute on a macroscopic level; few people would claim that, on the regional scale, it is cheaper to produce a sprawling, automobile-dependent environment than one that is compact and pedestrian- and transit-friendly. But, since the macro-scale costs of sprawling infrastructure are often absorbed by an unwitting government, developers must also be convinced that traditional development is cheaper at the smaller scale of the individual neighborhood infrastructure, which they must pay for.
Infrastructure wasted by the cul-de-sac system: gray streets have only 50 percent salable frontage. Black streets have no salable frontage at all
Take this typical subdivision layout, from an advertisement in the Detroit Free Press. In traditional neighborhoods, all streets except highways are “fronted” by salable lots on both sides; none of the infrastructure is wasted on transportation alone. But in this development by “Ann Arbor’s Premier Hometown Builder,” the roads marked in gray are fronted only on one side. Those marked in black have no building frontage at all; they are the automobile-only collector roads mandated by the dendritic cul-de-sac system. Not only is one third of the asphalt therefore redundant, but when one accounts for the fact that these roads are one-third wider than those found in traditional development, the cost of alleys becomes negligible. Further, since rear alleys eliminate the need for driveways, traditional urbanism provides savings there as well. In fact, alleys, if they are not overengineered, cost no more than the driveways they replace.
There is another way in which traditional neighborhoods offer savings over sprawl: they can be built in much smaller phases. Smart developers do their best to serve many different market segments at once—“starter,” “move-up,” “family,” “retirement,” and so on—but in suburbia they must build an independent pod for each market segment, since different incomes must never mix. In a traditional neighborhood, every market segment can be served through the construction of a single mixed-use area, thus limiting the infrastructure. Finally, there are the efficiencies that result from building at slightly higher densities, something that is viable within a traditional street network but is rarely achieved gracefully in sprawl.bk
To be fair, some developers of new traditional neighborhoods are quick to attest that they achieved no savings over conventional development. The reason is usually that these projects are hybrids: traditionally organized street networks that have been burdened with gold-plated infrastructure such as unnecessary collector roads, conventional street widths, and fully engineered curbs in alleys that are as thickly paved as streets. These compromises are typically required by old-school public works departments with no sympathy for different standards. It is only this sort of engineerimposed hybridization that threatens to bring the costs of traditional neighborhood development within the lofty realm of suburban sprawl.
STRUGGLES WITH THE HOMEBUILDERS
Even as land developers become aware of the true economy of traditional neighborhood design, there remains one