Opportunistic Park(ing): A Distributed Pedestrian Network

Thesis 2012: California College of the Arts
Instructor: Brian Price
By: Sean Stillwell

Abstract:

This thesis proposes ulterior means of producing public space within the city. 

My research has focused on where the current policy for public space making is ineffective and where there are opportunities to propose alternative strategies in both locating and implementing these spaces. 

This design experiment exploits an economy of means both politically and conceptually to illuminate how policy may be augmented to produce public space that will better serve the city.

Current Practices:

Within cities public space is typically created in two ways; the first method, as with Central Park in New York, develops huge acreages of land, often resulting in the displacement of marginalized groups. The gentrification of the Seneca Village community, located within the bounds of the new Central Park Plan was made possible through the exploitation of policy mechanisms such as eminent domain. 

1. Central Park Plan

By Oscar Hinrichs

en.wikipedia.org/wiki/Central_Park

2/3. Seneca Village: Plan & Artist Rendering

en.wikipedia.org/wiki/Seneca_Village

The second method, practiced in the downtown districts of cities such as San Francisco and New York, creates pockets of public space through policy mechanisms that trade public square footage for developer rights. While new development is obligated to make minimal square footages of public space on site, loopholes in city code are often exploited by the developers resulting in public spaces that are inaccessible to the general public due to sectional discontinuity with the sidewalk and mediated by building security. 

4/5. Privately Operated Public Open Space at 835 Market Street:

While this particular POPOS is more generous in area than a typical public space created through new development, the entrance to the building has no indication that this "public space" exists on its rooftop, and it is mediated by the building security, inaccessible after hours and on weekends.

sfcitizen.com/blog/tag/popos/

These POPOS, or privately operated public open spaces, are fragmented, limited to locations of redevelopment, and often inaccessible. Rarely are they located in the areas that lack public space, and as such, are indifferent to city wide demographics of high population density and areas of San Francisco with extremely low existing public space percentages. These public spaces do not contribute to the city.

6. POPOS Map: Map of San Francisco showing the location of public space resulting from new development. 

7. POPOS Elevation: These same spaces shown in a compressed elevation of the city.

Based on the limiting qualities of the POPOS I have determined that the metric of success is contiguous public space connected to, and often an extension of the limited pedestrian circulation network of the sidewalk.

8. Elevation: Existing/Desired condition of public space diagram.

Through analysis of San Francisco, specifically looking at population density and existing public space, I have determined that the Tenderloin neighborhood, located just north of Market Street in the heart of the city, typifies this dense condition. At 10% below the city average this neighborhood exemplifies where city policy for public space making has failed. These conditions provides the perfect example of an entrenched community where an architectural design experiment will illuminate how limited policy augmentation can achieve a more productive public space making plan for San Francisco. 

9. Population demographic: San Francisco

Source: The San Francisco Recreation and Open Space Element Plan, APRIL 2011

Architecture/Policy Precedents:

Precedent analysis provides strategies of architecture as policy; the ability to re-conceptualize space as public, as with Rebar's Park(ing) Day. 

10. Rebar: Park(ing) Day, San Francisco, CA.

rebargroup.org

Architecture also has the opportunity to provide an open frame work for programming and interaction, as with KGDVS & Dogma architecture's urban strategy for Seoul, Korea. 

11. KGDVS & Dogma architecture: Urban Strategy for Seoul, Korea.

www.icif.ru/engl/prize/prize/dogma.htm

Lastly, it has the ability to provide a pedestrian thoroughfare providing an alternative to, or extension of the sidewalk, expanding and contracting into a variety of public spaces. These strategies are exemplified in The Highline, by Diller Scofidio Renfro and James Corner Field Operations.

12. Diller Scofidio Renfro and James Corner Field Operations: The Highline, New York, NY. 

www.thehighline.org

While larger contiguous public space is the desired condition its implementation within a dense urban condition is problematic. This thesis seeks to develop a method that mitigates displacement and gentrification of the dense population that new public space is meant to serve.

In looking closer at the Tenderloin, I have identified abundant existing open space connected at grade to the sidewalk. The abundance of street level parking lots in the Tenderloin present an opportunity to raise the public space up to the city average of 17% without the demolition of existing buildings. 

13. Tenderloin Maps Urban/Neighborhood

14. Distributed vs. Localized public space

Design Constraints:

There are three main issues with parking lots being replaced by public space and relying on the sidewalk as a baseline for pedestrian circulation:

The first is that while these sites do offer an alternative to demolition of city fabric, the function of these parking lots are a necessary stream of tax revenue, especially for the generation of new public space for the city. This requires ulterior strategies to simply absolving them. 

The second issue is that while the existing sidewalk is necessary as an interface between pedestrians and cars, dependence on the sidewalk as a baseline for public activity is a limiting factor of the urban condition this thesis seeks to rectify. 

And finally, the limited scale of these new spaces and their dispersal is at odds with the desired continuous nature of larger successful public spaces that my proposal seeks to develop. 

Design Strategies:

Three design strategies can alleviate these issues. The first is creating these new public spaces one level above street level parking lots. This will not only insure that the stream of tax revenue from the lots will continue, but it will also develop these lots as covered parking, a benefit to the land owner.

15. Section diagrams showing the new surface of public space above street level parking. This surface is then subdivided to provide light and air below, negotiate sectional inconsistencies and grade connections, and provide a higher base level for bridging the street.

The second design strategy is to invert the city block, developing these new spaces as pedestrian thoroughfares through the block. By analyzing site lines to create minimal surgical cuts within buildings one level above grade, connections can be made from space to space within each block creating continuity. 

16. Polemic Image: These images illustrate the considerable difference that can be made by creating a network of spaces that act as pedestrian thoroughfares. In addition, the material choice can add to an intuitive understand of these spaces as "public" as with Rebar's Park(ing) Day (Fig. 10).

17. Site lines are used to create minimal surgical interventions within each block to connect these spaces at the scale of the block adding to the pedestrian network of the sidewalk. 

The third is to bridge between these new spaces to create a totally contiguous condition (Fig. 15). 

These strategies will create a new ground of public space liberated from the car centric city grid but alway connecting back to it. This enables a secondary pedestrian grain to occupy the city through a dispersed, but contiguous network of new public space, creating new sectional adjacencies and opportunities for innovation. While directly adjacent properties may organically develop as a new layering of retail spaces, social services, and the like, the site line cuts are designated as new frontage whose businesses will both activate and foster stewardship of these spaces.

18. Resulting Contiguous Space: Through minimal interventions within and minimal bridging between blocks a new pedestrian network is formed, always connecting back to the existing condition of the sidewalk.

Flexibility within this new ground of public space is required. Changes in topography, maintaining a 15'  clearance above the parking lots, fluctuation in floor hight of adjacent buildings all need to be negotiated. The quality of the parking lots below, conceived of beyond mere service spaces should also be designed with access for light, air, and visual connection to the public space above. These factors have lead me to subdivide this surface into programmable areas that can allow for the necessary sectionally shifts to occur (Fig 15). 

By projecting a structural grid compatible with the parking program below, the surface can be subdivided at multiple scales where each piece can be raised or lowered in section. 

19. Structural Strategy: By developing the programmatic organization of the new public space based on a 10' grid the parking program below will remain functional.

This system densifies at entrances and at the edges for sectional connectivity to the sidewalk and the first level of adjacent buildings and de-densifies in the center for larger programmable spaces desired in public parks. 

20. Grain Densification: The densest areas are where stairs and ramps are used to connect back to the sidewalk.

21. Site Plan: The plan indicates sectional connection to the street where the grain densifies, subsurfaces where programming can occur, and the new frontage produced through surgical site line cuts indicated by the blue line work. The red dashed lines indicating where there is building stock above. Programs B, C, and D are located towards the center of each space and have the area necessary for the listed programs.

A material strategy has been developed based on proximity to Market Street, the major public transit artery through San Francisco. The texture will remain consistent in the North-South axis to give directionality to the intervention and encourage foot traffic to venture further into the neighborhood. The materiality, on the other hand, will transition gradually from textured concrete closest to Market St. where the spaces are expected to have the highest use, to wood decking in the central spaces to give a boardwalk sentimentality, and permeable pavement and lawn system in the Northern extremes for a park-like feel to the spaces where the least amount of foot traffic is expected and where the majority of users will be the residents of the surrounding neighborhood.

Clarification:

An important aspect of the project to point out is that this thesis is not a programming exercise. While possible programs are indicated in the plan and represented in the rendered views, the specific programming occurring at each of these spaces would be developed individually through community outreach and polling with emphasis placed on providing the greatest resource for the local community.

Beyond locating and implementing new public space this thesis seeks to augment policy to require these new spaces as conceptually permanent. So while I am developing the tectonics of the system over the lots as relatively flexible and impermanent, new development of those lots would be required to maintain both the public space and the connectivity of the network.

22. Phasing: The distinct and disparate space would be developed separately as new funding from new development in the downtown zone allowed. As funding is allocated to two or more spaces within a certain proximity, bridging between them would be incorporated into the design process. The system would form "organically" with new development of the street level parking lots having to negotiate the conceptual permanence indicated above (Fig. 22).

23. Exploded Axonometric

24. Axonometric

Sidewalks, new public spaces, and existing parking lots can be integrated into a cohesive system. The resulting cuts through each block create new frontages and adjacencies that foster stewardship and promote successful public spaces.

25. Section Perspective

26. View 1: The experiential render illustrates how these spaces would be occupied and how possible programming of the new subdivided surfaces could play out. It also illustrates the contiguous nature of the spaces, how they bridge existing streets, independent from the car-centric grid, but always providing access.

In Conclusion:

Through these minor manipulations in public policy this thesis shows that architectural strategies have the ability to hijack the developer-centric process of public space making in downtown San Francisco and allow the city to create new public spaces at a per-neighborhood scale. 

Methodologies can be developed through architectural analysis that exploit local conditions while mitigating many negative affects of the new development of public spaces.

Special thanks to my Thesis Advisor, Brian Price, as well as the other section instructors, Natalie Gattegno, Hugh Hynes, and Neal Schwartz for all of your critical insight throughout the research process.