Changing the Density Equation for Suburbs

Sidewalk PedestrianSince the beginning of America’s suburban experiment, it has only been recently that effort and interest has welled behind the ideas of walkability and alternatives to a car-centric life outside of cities. While movements like New Urbanism that promote re-investigating the suburban model have swelled with support over the past decade, these projects still represent a minority in development outside of urban centers. Even when aspects like tenets of New Urbanism are employed, the goal of increasing walkability in American suburbia faces an uphill battle until more substantial steps can be taken to alter the parameters for both construction and mobility. Re-orienting the suburbia we know for the pedestrian is inherently fighting against its own DNA.

Our suburbs realize the goal of spreading things farther apart because their creators were presented with a new option for traveling longer distances in a shorter amount of time. The world of sub-divisions constructed on tracts of greenfield acreage was built upon an idea of mobility, even if that idea meant that residents would have to spend more time being mobile. The propagation of the detached, single-family home was designed for communities of private space, even if that separation came at the expense of community interaction.

In many ways, the heart of the problem revolves around density; how to achieve the proximity of people and services necessary to make a walkable landscape function when starting with a town built for the purpose of spreading out. Short of mowing down communities and starting with a clean slate (which some architects like Paolo Soleri believed is the only solution for suburban America) the process can start by changes to local zoning to incentivize a migration to more walkable development patterns.

Come on Over, Neighbor

In order to increase density where it is wanted (near a town center) and discourage expansion through sprawl (at the periphery) a municipality could create a market for density where one doesn’t exist with a trade. By creating new peripheral areas dedicated for conservation paired with zoning changes in the town center, the market forces of development could change to promote a more walkable outcome.

The plan would start with the identification of conservation area, presumably on the outer edge of a municipality and anchored with existing natural features like forests, wetlands or bodies of water. In addition to land untouched by development, the town would include private property currently owned by residents, creating the option for the land beneath them to be added to the preserve at any point in the future. While there is nothing limiting any homeowner from adding restrictive covenants to a property for conservation purposes, these plots would have the capacity to transfer a portion of their square footage back into property in the center of town (or a transit oriented development site) to allow the owner to build beyond normal zoning restrictions.

Conservation Town Center Density

(click to enlarge)

With the correct calibration, it should be possible to create financial incentive for all parties involved. The peripheral homeowner could still have a healthy sale price for their home given that there is no depreciation to the land and they are under no pressure to sell. A potential buyer (who would theoretically also own land in the town center) would be buying less expensive acreage for the opportunity to build bigger or taller more expensive acreage. To sweeten the deal a bit more, the donation of the conservation land could most likely earn the buyer a tax credit of some sort as well (with the requirement that the existing home be sustainably demolished and returned to native land). The town should get a net increase of tax base while local business gets an influx of nearby customers.

The particulars of the final formula would be location specific, depending a great deal on things like the availability of land, the current levels of infrastructure, housing demand and financial market forces. But the feasibility lies only in a town taking a proactive role in deciding its own future.

Simple Moves with Many Benefits

Efforts like this can function as part of a larger initiative for walkable communities, complimenting things like taxing greenfield construction to subsidize infill (more about that here). Coordinating a density transfer could help bolster a migration towards a pedestrian culture. As density rises in close proximity, local businesses that count on sidewalk frontage rather than parking spaces become more viable. A reality of ground floor retail is contingent on a healthy flow of pedestrian traffic. Be it a restaurant, grocery story or dry cleaner, every trip taken by foot is a trip that isn’t taken by car.

Charles Marohn, author of Strong Towns, points to the inability of some suburban municipalities to finance their own existence in the absence of consistent growth. Marohn argues that the lack of density in our popular suburban model inherently robs municipal systems of their financial solvency, requiring new generations of growth to pay for the infrastructure of the ones before. On the flip side, localized density lends itself to a more reliable infrastructure grid that costs less per capita and is easier to maintain.

As the amount of residents per unit of area rises, the cost to provide basic services to them drops and options that last longer (like underground electrical instead of poles and power lines) become better investments for both utilities and consumers alike. The process could be bolstered further by instituting utility prices based on a density-driven grid where homes farther from central distribution points need to pay more to help finance utilities stretching out to reach them. If the outermost reaches of local development are shuttered for conservation in favor for a tighter town center, roadways that used to need paving and plowing can be abandoned or even removed to reduce impervious surfaces.

The integration of modes of alternative transit have always faced stiff headwinds in suburban America where the sprinkling of homes over large distances make it impossible to justify the costs of installation and operation of transit systems-even municipal buses. As development patterns change, the equation for alternative transit could begin to change in an environment where it has consistently been ruled unfeasible. With enough businesses in close proximity and enough potential users close enough to make a car trip unnecessary, the criteria for bike lanes or bus routes could be more plausible.

Every town having a stock of land that is off-limits to development isn’t bad either. These areas where nature is allowed to define its own destiny serve as permanent carbon sinks and natural filters for air and water. Proactive steps to identify more outdoor spaces worth saving will help ensure that people have native landscapes to utilize for recreation (a reason that many suburban dwellers give for living outside of the city in the first place). On top of that, more local habitats and natural ecologies will remain intact.

Don’t Wait for a Game Changer, Just Change the Game

It is one thing to challenge the model when starting from scratch, but changing the existing suburban fabric is more challenging. Context is an amazing source of inertia for the status quo. Building a bridge over a river is often less difficult than replacing the bridge. When you start all there is a river to cross. It can take as long as it needs to and the result will be access where none previously existed. Replacing the bridge means either stopping people from crossing the bridge they’re already using, or building a temporary bridge to divert the current traffic, removing the existing bridge, building a new one and removing the temporary one. In the same way, working with the suburbia we have makes for a difficult problem when it comes to an option other than vehicular travel, which in turn influences the size and type of use groups that will follow.

The design community has already spent some time talking about the obstacles for altering the trend of suburban development. In many cases, efforts of designers and planners try to tweak individual buildings, streets or intersections within a broken regulatory system–effectively trying to make a better widget. The maturity of the evolutionary development of suburban America puts us past the point where tweaks and nudges will provide the re-calibration necessary for walkable communities. Eventually we need to change the rules of the game if we want to alter the outcome.

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