Sunday, July 5, 2009

Regenerative Suburban Planning

A striking issue with the development model of the last several decades is that it relies on packing the McMansions onto winding deadend streets that are completely auto dependent and isolated from town centers and parks. New Urbanism has tackled this to a certain extent by moving to a more dense model that shortens auto driving by going back to the old town street grid, as well as an integration of uses that mimics the city-center density model with a mixed-use emphasis. This unfortunately tends to force creation of a tremendous amount of structure into a landscape that is already withering under the onslaught of human habitation.

What if a GREEN "Pattern Language" - as was developed by Christopher Alexander for designing human spaces - used a vocabulary of low-impact and regenerative structures and landscape, driven by natural vectors - not just economic ones - to restore overdeveloped areas and return watershed and landscaping to nature? This would be an application of the residential end of the Green Transect development spectrum.

This pattern would begin with the "building block" of homes that use the characteristics of the site and its orientation to the sun and wind. This creates lots that are driven by the east-west axis placement and orientation to the south sun that can be tempered with trees and overhangs. This also creates more opportunity to use trees and natural landscaping to absorb the rain that falls onto the area.
We begin to build this pattern into a "play street' that is designated as residential access only with trees and landscaping instead of driveways:
Then we begin to cluster these patterns around a car and utility access system that also provides private play areas for the adjacent homes. This is far more efficient than the old utility distribution, and supports the creation of "distributed utilities" in a hub system, facilitating the development of "smart grid" technologies and reducing the expense and cost of providing utility connections. The mail chests would be located here, as well, for efficient delivery/pickup.
If renovated and infill suburban tracts were rebuilt on this more efficient model, then the ability to supply grey water from local mini-treatment facilities to a landscape irrigation system becomes completely feasible. The urban area becomes a means of supplying water to the aquifer which has already been imported by human consumption (to be delicate about it). This reflects the "soft path" model of infrastructure integration referred to in my earlier post.
Ultimately, this model for the neighborhood can link together as a tight grid with alternating traffic streets and play streets, with the homes oriented so as to use the natural topography and solar orientation in a passive system that reduces the impact of development. Added to this are the grid and utility efficiencies, and the limitation of auto traffic to the streets that access the motor courts. The "play streets" are identified and accessed through a restricted auto entry that uses mature specimen trees to define these streets. What becomes immediately apparent is the ability of the residents to walk or bike through the neighborhood access ways without confronting auto traffic except every other block. This "through way" access (paved with DG) replaces traditional sidewalks along the streets, which are no longer needed. The entire neighborhood ultimately becomes a means of using the urban tree canopy - and keeping it watered - that offsets the dense urban centers creating the "urban heat island" effect.
This is the same sort of exercise that was used in San Francisco to generate the urban forms and use patterns for the Treasure Island redevelopment, as I posted earlier.