Letterman Complex Final Planning and Design Guidelines

 

Chapter 1 TITLE PAGE


 

1.  INTRODUCTION AND PURPOSE                                             B-1

2.  SETTING                                                                     B-3

2.1   National Park in an Urban Setting                                                                                                                     B-3

2.2   National and Regional Context                                                                                                                          B-3

2.3   National Historic Landmark District                                                                                                                  B-3

2.4   A Physical History of the Letterman Hospital                                                                                                B-4

2.5   Architectural Characteristics of the Letterman Complex                                                                               B-9

2.6   Goals for Environmental Sustainability                                                                                                          B-12

3.  PLANNING GUIDELINES                                                    B-13

3.1   Planning Guidelines:  Land Use And  Public Access                                                                                  B-14

3.1.1 Design Principles                                                                                                                                      B-14

3.1.2 Guidelines                                                                                                                                                  B-14

3.2   Planning Guidelines:  Natural Landscape                                                                                                      B-19

3.2.1 Design Principles                                                                                                                                      B-19

3.2.2 Guidelines                                                                                                                                                  B-19

3.3   Planning Guidelines:  Cultural Landscape                                                                                                     B-24

3.3.1 Design Principles                                                                                                                                      B-24

3.3.2 Guidelines                                                                                                                                                  B-27

3.4   Planning Guidelines: scenic views                                                                                                                  B-32

3.4.1 Design Principles                                                                                                                                      B-32

3.4.2 Guidelines                                                                                                                                                  B-32

3.5   Planning Guidelines:  Building Form                                                                                                               B-36

3.5.1 Design Principles                                                                                                                                      B-36

3.5.2 Guidelines                                                                                                                                                  B-36

3.6   Planning Guidelines:  Access, Circulation,  and Parking                                                                             B-46

3.6.1 Design Principles                                                                                                                                      B-46

3.6.2 Guidelines

3.7 Design Review Process

4.  ADDITIONAL RESOURCES                                                  B-55

5. glossary


LIST OF FIGURES

 

1            Project Boundaries:  Letterman Complex                                                                                              B-2

2            Letterman Complex 1907                                                                                                                         B-5

3            Letterman Complex 1915                                                                                                                         B-6

4            Letterman Complex 1918                                                                                                                         B-7

5            Letterman Complex 1943                                                                                                                         B-8

6            Letterman Complex 1990s                                                                                                                       B-8

7            Buildings 1050 and 1051                                                                                                                       B-10

8            Building 1047                                                                                                                                          B-11

9            A Narrow Courtyard Between Buildings 1008 and 1009                                                                  B-11

10          Land Use and Public Access                                                                                                               B-15

11          Major Open Spaces                                                                                                                               B-18

12          Natural Landscape Elements                                                                                                                B-20

13          Critical Elements of Natural and Cultural Landscape                                                                       B-21

14          Cultural Landscape Infrastructure                                                                                                      B-25

15          Cultural Landscape Elements                                                                                                               B-26

16          Pattern of Development                                                                                                                        B-31

17          Letterman Courtyard                                                                                                                             B-33

18          Scenic Views

19          Thornburg Avenue

20          Palace of Fine Arts

21          Historic Pattern of Letterman Development (Photo)

22          Historic Pattern of Letterman Development (Plan)

23          Edge Conditions

24          Edge Condition at O'Reilly Avenue

25          Edge Condition at Gorgas Avenue

26          Edge Condition at Lyon Street                                                                                                            B-39

27          Height Zone Diagram                                                                                                                            B-40

28          Building 86

29          Building 1047

30          Building 1016

31          Building 1014                                                                                                                                                 

32          Vehicular Circulation                                                                                                                             B-47

33          Pedestrian Circulation                                                                                                                           B-50

34          Current Bicycle Circulation                                                                                                                  B-51

35          Current Transit                                                                                                                                       B-52

 

 


1. INTRODUCTION AND PURPOSE


The Guidelines outlined in this document provide a planning and design framework for the entire range of actions expected in the 23-acre site, but also apply to undertakings that fall short of new construction, such as site improvements and historic building rehabilitation for the 60-acre Letterman Complex. Among the topics covered in the guidelines are new building construction on the 23-acre site, improvements in transportation systems and infrastructure; design and maintenance of the natural and cultural landscape; and rehabilitation of historic structures.  They are to be used in conjunction with other guidelines already in place such as the Secretary of the Interior’s Standards for Treatment of Historic Properties with Guidelines for Treatment of Cultural Landscapes (NPS 1996) and the Guidelines for Rehabilitating Buildings at the Presidio of San Francisco (NPS 1995). The Planning and Design Guidelines should not be viewed as rigid rules.  They have been prepared to serve as guides as the project moves through the process of negotiation, the signing of a lease, or the execution of a development agreement.  The Trust’s intent is to ensure that the project design and construction conforms as closely as practicable to the Planning Guidelines and design guidelines. They are envisioned as a continuing, interactive set of guides which would continue to provide guidance after the environmental review process for any action is concluded.

The Planning and Design Guidelines begin with a description of the general context within which the Letterman Complex will take shape—its status as a national park, its designation as a National Historic Landmark, and its role as part of the Golden Gate National Recreation Area (GGNRA).  A brief history of the Letterman Hospital, and broad sustainability policies are also outlined. This section is followed by guidelines for six broad categories: Land Use and Public Access; Pattern of Development; Scenic Views; Cultural and Natural Landscape; Building Form; and Access, Circulation, and Parking.  The next section describes briefly the design review process. In each category, planning and design principles are outlined, and specific guidelines are presented in the form of diagrams and text.  The section called Additional Resources provides a rich source of background information relating to the Presidio.  The final section is a glossary of terms used in the guidelines.

The Presidio is within the boundaries of the GGNRA. The 60-acre Letterman Complex is one of several planning areas within the Presidio, which the 23-acre development site occupying its eastern portion (Figure 1). The characteristics defined below represent the overarching policy setting of the Presidio that should be considered in the planning and design of new construction:

n   A national park in an urban setting

n   National and regional context

n   National Historic Landmark district

-A Physical History

-Architectural Characteristics

n   Goals for  environmental sustainability


 

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Figure 1. Project Boundaries: Letterman Complex

 

 


2. SETTING

2.1     National Park in an Urban Setting

The Presidio is a unit of the GGNRA, which was established by Congress in 1972 and consists of a collection of parklands surrounding the San Francisco Bay and nearby environs.  Many of the parts of the GGNRA are, like the Presidio, former military holdings. The goal of establishing this urban national park was to preserve “for public use and enjoyment” areas possessing outstanding cultural, natural, historic, scenic and recreational values. The Presidio’s distinctive resources include its historic architecture and landscapes, unique ecological systems and rare plant communities, inviting parklands, spectacular views and recreational resources.  The Presidio attracts visitors who take advantage of interpretive programs and exhibits, and visit the historic military sites, as well as those who enjoy the natural resources, open space and scenery.

2.2     National and Regional Context

By making its array of cultural, natural and recreational resources accessible and available, the GGNRA provides educational and recreational opportunities for the metropolitan population of the Bay Area, as well as for visitors from across the nation and around the world. The GGNRA parklands represent one of the nation’s largest coastal preserves, attracting 20 million visitors a year, more than any other unit of the national park system.  Nowhere else in the national park system is a span and variety of history represented that is comparable to the 220-year continuum of the Presidio’s use as a military garrison, occupied by Spain, Mexico and the United States. During its history, the Presidio has played a logistical role in every major U.S. military engagement since the Mexican-American War. It tells the story of the colonization of California, the settlement and exploitation of the American frontier, the Gold Rush, the growth of the city of San Francisco, the Asian immigration, and the evolution of U.S. involvement in the Pacific region.

2.3     National Historic Landmark District

A National Historical Landmark is a property of national historical significance as designated by the Secretary of the Interior under the authority of the Historic Sites Act of 1935.  The Presidio of San Francisco was designated as a National Historic Landmark in 1962, with an update designation in 1993. It is recognized nationally as a Spanish colonial and then Mexican military settlement (1776–1846) and a major U.S. Army post from 1846 through World War II.

The 1993 update defines the Presidio’s “period of significance” as spanning the years 1776 to 1945, and 1951. Buildings and features are considered to be historic (and thus contributing to the National Historic Landmark status) if they were constructed during the period of significance and still retain their integrity.  Of the Presidio’s 780 buildings, approximately 470 are historic and classified as “contributing features” to the National Historic Landmark district. The Letterman Complex contains 44 buildings; all but 9 are historic.

A historic district, such as the Presidio, consists of more than just individual historic buildings. It also includes the “cultural landscape.” The cultural landscape is defined by land use patterns, and includes clusters of buildings, circulation networks, open spaces and vistas, and small-scale distinguishing features.  Cultural landscapes include not only plant material, grading, and other typical landscaping elements used to shape the natural landscape, but are also include the way that the physical environment is transformed on a larger scale by site organization, building form, and circulation.  On the Letterman Complex, elements of the cultural landscape include traces left by the layout of the historic hospital complex, as well as that of the 1915 Panama Pacific International Exposition.  Remnants of the site’s past include buildings from the historic hospital complex, street layouts, open spaces, and a distinct approach to landscape design.  Each of these elements evokes the site’s history and contributes to Letterman’s unique character. New construction and building rehabilitation that is planned within a historic district must respect the integrity of the district, and recognize the character-defining features of both the architecture and the cultural landscape.

2.4     A Physical History of the Letterman Hospital

2.4.1  Original construction and early years

The land selected for the construction of the Letterman Hospital at the eastern boundary of the Presidio was partially bounded on its east and north edges by a slough and salt marshes (located on the Lyon Street edge, in the area north of Chestnut Street). Many considered this a poor location for a hospital, but others argued that its proximity to the city of San Francisco would be advantageous. This was one of the few edges of the military reservation where the U.S. Army and the city came face-to-face. The exact boundary of the Presidio along its eastern and southern edges had been contested for many years by the city of San Francisco, leading to a final court decision which established Lyon Street as the eastern edge of the Presidio in the 1870s.  Non-military business enterprises at the Presidio’s eastern edge, such as the public resorts known as Presidio House and the Harbor View Resort, attracted citizens to the Presidio’s border, and offered recreation to Army personnel, as early as the 1860s.  The establishment of rail service, in the form of steam trains, brought people to these resorts by the 1870s.  With the establishment of the Letterman Hospital, a cable car line was brought into the Presidio as an extension of the Greenwich Street line, terminating in front of the main hospital building.

Construction of the Letterman Army Hospital, originally designated as the U.S. Army General Hospital, began in 1898 to accommodate soldiers during the Spanish-American War. The original hospital complex was designed as a 300-bed pavilion style hospital with the buildings, including wards, administrative buildings, operating theater, kitchen and mess halls arranged symmetrically around a centrally planted quadrangle. Most of the individual buildings were connected together by a glazed gallery that allowed easy access for soldiers in wheelchairs and gurneys. By 1904, additional buildings, such as an operating pavilion in the center of the quadrangle, the powerhouse, a laundry facility, two officers’ residences, more barracks, and wards were constructed (Figure 2.)


 

2.4.2  The Panama Pacific International Exposition Map

Figure 2.  Letterman Complex 1907

 
The Panama Pacific International Exposition

The Panama Pacific International Exposition was a celebration of the opening of the Panama Canal, and was designed to showcase the revival of San Francisco after the 1906 Earthquake. Acres of swampy shoreline, in the neighborhood now known as the Marina, were filled in to create a level site for the fair. Based on a “city beautiful” concept of symmetrically laid out streets and blocks, it featured grandiose Beaux-Arts exhibition buildings and exotic landscaping. The Army, cooperating with the exposition organizers, allowed a significant portion of the exposition to be placed within the boundaries of the Presidio. It occupied all of the current 23 acres to the east of the original hospital (later to be known as the East Hospital site), the Gorgas Avenue warehouse area, and the area currently known as Crissy Field.(Figure 3.) Work began on the site in 1912, and the exposition opened to the public in 1915. Due to the outbreak of World War I in Europe, it closed after less than one year in operation.  The Palace of Fine Arts is the only building remaining from the exposition. The Army reclaimed its land, putting the manmade flat land to immediate use as an airfield. The layout of Gorgas Avenue, Mason Street, and other streets in this area remain to this day. The road system laid out by the Exposition planners remained in part as the basis for the East Hospital street system, which remained until the early 1960s.

 

  Letterman Complex 1915 Panama Pacific International Exposition Map

Figure 3.  Letterman Complex 1915

Panama Pacific International Exposition

 

2.4.3  World War I

By World War I, Letterman Hospital had expanded significantly with the construction of four additional officers’ residences along O’Reilly Avenue, new nurses quarters, kitchen and dining room, new stables, temporary barracks and quartermaster storehouses. By 1918, the utilitarian structures such as the laundry facility, the detention ward and the psychiatric ward were constructed along Thornburg Road. The East Hospital was constructed as an ancillary hospital to accommodate the vast number of incoming wounded soldiers. The new hospital complex included 18 patient wards, two barracks, kitchen and mess hall, and a Red Cross building (Figure 4.)  The YMCA constructed a building on Lincoln Boulevard, across from the hospital, to provide recreational space for the soldiers. Old roads were paved and new roads were built during this time.

Letterman complex 1918 Map

Figure 4.  Letterman Complex 1918

 

2.4.4  Between the Wars

Following World War I, Letterman Hospital continued to grow. Patients continued to arrive from the Philippines, Hawaii, China and other western military installations. New medical programs were initiated and additional buildings were constructed to support these activities. During the 1930s, the hospital’s commanding officer was concerned about the condition of the original wood-frame structures, viewing them as lacking in modern requirements and as potential fire hazards. He ordered the replacement of the simpler wood-frame wards and clinics with larger, concrete ones. Buildings 1009, 1012, 1013 and 1014 , which still stand today, were built for this reason.

2.4.5  World War II

The attack on Pearl Harbor placed Letterman Hospital in a combat zone.  By 1942, the hospital served the triple function of being a port of embarkation, a general hospital and an evacuation hospital. Staggering numbers of sick or wounded soldiers from the Pacific were shipped to the hospital, making Letterman one of the busiest military hospitals in the country. Letterman Hospital took command of the temporary housing cantonments recently built on Crissy Field and used them as overflow hospital buildings. New, temporary wood-frame structures were built throughout the East Hospital area, including three Special Service schools, administrative and barracks buildings and a new mess hall. This period represents the maximum building density on the site, with new buildings placed on previously open areas, some very close to the site’s boundaries (Figure 5.) Despite the new density on the site, open space was always maintained between buildings so that daylight and natural ventilation reached each building.  A system of linked buildings connected by enclosed galleries continued to be used. The Letterman Hospital served as a self-contained city within the Presidio, consisting of medical buildings, wards, service and utility buildings, recreational and entertainment facilities, housing, storage and warehouses, a laundry, food service, vegetable gardens and greenhouses.

 

Letterman Complex 1943 Map

Figure 5.  Letterman Complex 1943

 

2.4.6  Post–World War II

After World War II, the military started planning a more modern hospital, although plans were temporarily stalled during the Korean War. By 1965, Congress authorized the construction of a new hospital and between 1965 and 1976, much of the original hospital quadrangle buildings and all of the East Hospital were removed to make way for the new structure. In 1968, a new 550-bed, 10-story building was constructed and was named Letterman Army Medical Center (LAMC) in 1973. Between 1971 and 1976, the Army constructed the Letterman Army Institute of Research (LAIR), new nurses quarters and an administrative supply building (Figure 6.)  In the post-World War II era, the hospital’s role changed from serving wounded soldiers to serving the military community living in the region. Its role became that of a regional medical center, with emergency rooms and clinics, providing health care to active and retired military, and their dependents. 

Letterman Complex 1990's Map

Figure B-6.  Letterman Complex 1990s

2.5     Architectural Characteristics of the Letterman Complex

The Letterman Complex was administratively separate from the rest of the Presidio, and developed differently from the majority of the buildings constructed elsewhere in the Presidio by the Army.  It was a self-contained entity, and for this reason, maintained a visual appearance and development pattern that is distinctive within the Presidio.

The following is a summary of the architectural character-defining features of the historic buildings at the Letterman Complex:

n   The majority of the buildings are very plain, with little applied decoration. They are simple, straightforward buildings (see Figure 7).

n   Throughout the Letterman Complex, building form is determined by function.  Considerable variety is evident in building shape and size, as a result of the broad mix of functions housed in the buildings.

n   There is a broad range of building types in the Letterman Complex, ranging from residential, administrative, and medical to service buildings and warehouses.

n   Architectural detail and materials are used to differentiate the ceremonial, public buildings from the service and functional buildings. Architectural detail and decorative features are used sparingly.

n   Buildings are typically very long. Long, thin buildings are characteristic of military architecture found throughout the Presidio.

n   A basement story is often clearly visible. Because of the slope of the site, the basement story is often fully above ground, at least on one side of the building.

n   Buildings have tall floor-to-floor heights, but are frequently rather narrow, resulting in a distinctive proportion.

n   Fenestration is characterized by tall, thin windows, which are used singly, in repetitive “punched openings” (as is seen in a hospital ward building) or grouped together to create large expanses of glazing (as is seen on galleries, the gymnasium or laundry).

n   Building elevations are highly regular in organization.  The placement of window and door openings is carefully laid out according to symmetry and geometric regularity.

n   Buildings have overhanging eaves. Frequently, the eave line of a building contains decorative architectural elements (see Figure 8).

Building groups at the Letterman Complex also have defining characteristics, including:

n   Building complexes, sometimes of a very large size, created by linking smaller buildings with breezeways, enclosed galleries, and other connecting devices, to create connected building ensembles.  (see Figure B-9)

n   A common color scheme and palette of building materials unify the diverse collections of buildings at the Letterman Complex.

n   The buildings of the historic hospital complex were laid out in a clear hierarchical pattern with public buildings facing the southern edge of the site, service buildings on the north edge, and internalized courtyards and open spaces which were private, or intended only for users of the complex.

Exterior spaces also have distinctive characteristics at the Letterman Complex, including:

n   A system of courtyards and open spaces that are defined by building edges formerly existed. Today, only the spaces between the former ward buildings and the central parking lot of the Thoreau Center for Sustainability remain (see Figure 9).

n   Thornburg Road is a narrow space with an urban character.  Its uniform street walls create a clearly defined exterior space, whose scale is very inviting for human activity.

n   Gorgas Avenue is a wide, utilitarian street. Most of its buildings are warehouses with loading docks.  Its width and the architectural character of the buildings which define its edges create an “industrial thoroughfare” which is consistent for most of its length.

 

 

Picture of Buildings 1050 and 1051 are examples of linked buildings

 

Figure 7.  Buildings 1050 and 1051

are an example of linked buildings.

 

 

 

 

 

 

 

Picture of Building 1047 contains decorative elments in its eave.

 

Figure 8.  Building 1047

contains decorative elements in its eave.

 

Picture of a narrow courtyard between buildings 1008 and 1009 is one fo the few which remain in the historic hospital complex

 

Figure 9. A Narrow Courtyard Between Buildings 1008 and 1009

is one of the few which remain in the historic hospital complex.

 

2.6     Goals for Environmental Sustainability

The General Management Plan Amendment (GMPA) states that the Presidio will be a “model of sustainability” by using and demonstrating innovative environmental technology applications.  Design for the Letterman Complex should adopt the principles of sustainable design and technology when upgrading the built environment.

Sustainability is an approach to design that recognizes that every design choice has an impact on the natural and cultural resources of the local, the regional and the global environment.  At Letterman, it is expected that rehabilitation of historic structures, removal of existing buildings, new construction, and changes to the landscape will take place. Each of these actions has environmental consequences, and for each action, sustainable practices must be applied. These practices must start at the inception of the project’s planning phase, and extend through the life of the building or site. The following recommendations address ways by which sustainability can be achieved at the Presidio:

n   Respect and respond to the unique characteristics of each site, but recognize the interdependence of all actions on the planet.

n   Conserve energy by minimizing the initial energy expended by construction requirements and by using systems that minimize energy for the operational future of the building.

n   Use environmentally responsible building materials.

n   Conserve water by reducing consumption and recycling rainwater and gray water.

n   Provide a healthy environment by reducing or eliminating the use or release of toxins and pollutants.

n   Reduce or eliminate waste by eliminating consumption, reusing materials, and recycling.

n   Design landscapes that are drought tolerant and incorporate water conservation measures.  

n   Decrease the use of the private automobile, and increase the use of public transportation, bicycle and pedestrian circulation.  Explore alternative means of transportation that have fewer negative environmental impacts than automobile use.


3. PLANNING AND DESIGN GUIDELINES

The following section presents planning and design guidelines for the 60-acre Letterman Complex that address issues of site planning, public access, landscape, transportation, building massing and scale, and architectural design.  Broad design principles are outlined and followed by specific guidelines for their application.

The ultimate goal of the Planning and Design Guidelines is the facilitation of design excellence in all new building and development on the 23-acre site.  It is a firmly held belief that good design creates both value and an enduring sense of place.  The principles and guidelines contained in the following pages reflect that belief and are meant to serve as guidance for new design within the Letterman Complex.  To this end, these Planning and Design Guidelines should be viewed as a set of recommendations rather than rigid rules.  Creativity and innovation are strongly encouraged and the design review process will provide the opportunity for individual designers to make the case for variations.

The Guidelines are divided into six categories:

n   Land Use and Public Access

n   Natural Landscape

n   Cultural Landscape

n   Scenic Views

n   Building Form

n   Access, Circulation, and Parking

Each section outlines important design principles and guidelines for future action and should be considered together for a complete picture of the goals for the Letterman Complex.

 


3.1 Planning AND DESIGN Guidelines:  Land Use And
Public Access

Located adjacent to dynamic city neighborhoods and bustling visitor destinations, the Letterman Complex is the most urban among all sites within the Presidio.  Historically as well, at the time of the Panama Pacific International Exposition and during its peak as a military hospital during World War II, Letterman was one of the most dense, active areas within the Presidio.  The key to successful redevelopment of the Letterman Complex lies in regaining this vitality by creating a diverse, lively, publicly accessible community.  The Letterman Complex should incorporate a variety of resources and activities that serve employees, residents and visitors to the site and create a dynamic public setting appropriate to its stature as part of a national park. 

3.1.1  Design Principles

n   Establish a planning and design setting at Letterman that encourages and accommodates a wide range of uses, reinforcing the Presidio as a unique community in which to work, visit or live.

n   Integrate public access with private development to the benefit of both.

n   Locate land uses that invite public use along major access routes and in association with public streets and open spaces.

n   Encourage visitors and promote educational, interpretive, and recreational amenities, consistent with Presidio-wide plans.

n   Enhance linkages between the Letterman Complex and the rest of the Presidio, and, as possible, with the city.

3.1.2  Guidelines

A. Land Use

New public open space areas within the Letterman Complex should be sited to take advantage of key visitor circulation corridors.  To that end, it is recommended that visitor-serving uses be located on the edges of the Letterman site.  These “Public-Use Focus Areas” are identified in Figure 10 and include areas around Gorgas Avenue, Thornburg Street, and Lombard Street/Letterman Drive.  The general area between these two zones, identified in Figure B-10 as the “Working Core,” is envisioned to contain uses related to the everyday working of the new Letterman development, including, but not limited to employee and resident amenities, service areas, and parking.  In addition, a network of public open spaces and pedestrian connections is proposed to enhance public enjoyment of the site.  This general land use diagram would vary depending on the mix of uses at Letterman and a particular project’s needs as to access, service and amenities

n   Lombard Street/Letterman Drive Public-Use Focus Area

Sited along the historic and gracious Lombard Street Gate entry into the Presidio, this edge of the Letterman Complex is the formal “front door” to the site as well as to the Presidio as a whole.  Public uses with a strong focus on education and interpretation of the area’s historic, cultural, and natural resources are encouraged.
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Figure 10.  Land Use and Public Access


n   Gorgas Avenue/Thornburg Road Public-Use Focus Area

This area is expected to be the active, event-oriented, urban face of the Letterman Complex, as it contains the primary vehicular entry to the site.  Retail, recreational, and cultural program uses that reinforce connections to nearby destinations such as Crissy Field, the Marina, and the Palace of Fine Arts may be accommodated in this area.  Public access should be encouraged through strategic location of ground floor uses, where the upper levels of buildings may be devoted to more private uses.

n   O’Reilly Commons

An open space referred to as the O’Reilly Commons should be created between the historic O’Reilly Avenue houses and the new construction which faces it.  This area should be a significant and usable public open space that is sensitive to the historic character of the O’Reilly houses and their landscapes, and makes the transition to the 23-acre new development area to the east. An average distance of 125 feet should be maintained between the face of the historic structures and the new buildings. New buildings which border the commons should present an inviting face to this public open space.

n   Letterman “Working Core”

The heart of the new development in the 23-acre parcel, east of the O’Reilly Commons and set back from the public edges along Gorgas Avenue and Lombard Street/Letterman Drive, may be seen as a “Working Core.”  This area could contain uses that are not highly public and are oriented to the users, employees, and residents of the Letterman Complex.  Employee amenities, intimate courtyards and open spaces, parking structures, service and loading docks, and support facilities may be located in this “Working Core.”

n   Other Sites

New uses and programs developed for the western part of the Letterman Complex, outside the 23-acre site, should be compatible with the historic buildings in which they would be located.

B. Visitor Experience

n   The site is part of a national park, open and accessible to all visitors. Places where visitors are welcome should be created, preferably within the “Public-Use Focus Areas,” that showcase and interpret the history of the Letterman Complex and relate to other Presidio themes and national park visitor experience.  This might take the form of a Letterman visitor center, a museum, a walking tour, or some other point of interest that can be developed in conjunction with the Presidio Trust and NPS.  Alternatively, visitors might be invited to learn more about the working activities of tenants in the Letterman Complex by showcasing their work, their research into environmental policies, or their experimentation with technology, sustainable practices or other related activities.

n   The future use of building 558 (identified in Figure 1) may be as a visitor information center or similar public use building.  Because this location receives a large amount of traffic from the Lombard Street and Presidio gates, it could easily become a special destination for visitors.  Consider the benefits of establishing a relationship between building 558 and the O’Reilly Commons. 

n   Create attractive and inviting edges and entrances to the site. Connect to existing trails as well as to planned systems of pedestrian and bicycle paths.

C. Public Access and Open Space

n   Create a network of public open spaces within the Letterman Complex, whose four major components are the O’Reilly Commons, the historic Lyon Street Windrow, the Letterman Courtyard (current parking lot west of the Thoreau Center for Sustainability) and the Lombard Green. They are identified in Figure 11. Establish pedestrian links between these open spaces.

n   Provide strong pedestrian and bicycle connections to link the Letterman Complex to adjacent neighborhoods and city destinations such as Crissy Field, Main Post Parade Ground, the Marina, the Golden Gate Bridge, and the Palace of Fine Arts.

n   Develop a hierarchy of open spaces in the new Letterman development which respects existing patterns — from large, public open spaces to intimate courtyards, in a linked network that takes cues from historic patterns of development.

n   Within new structures in the Letterman Complex, locate retail, cultural, educational, and visitor-oriented uses on the ground floors of buildings as appropriate in order to create a pedestrian-friendly, visually interesting environment at the street level.


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Figure 11.   Major Open Spaces


3.2 Planning Guidelines:  Natural Landscape

This section deals with design issues that involve the dynamic natural processes at work on the site.  Geological, hydrologic, climatic, and ecological forces created the physical conditions that the Presidio’s first inhabitants found. These factors continue to operate on the site independent of human activity, and they must be taken into account as people continue to use and transform the site.

The 60-acre Letterman Complex includes four significant natural components (shown in Figure 12, Natural Landscape Elements, and Figure 13, Critical Elements of Natural and Cultural Landscape).  The first is the topography, which slopes gradually north toward San Francisco Bay and accounts for the site’s even drainage pattern and its spectacular views to the Palace of Fine Arts and the bay.  The second is Tennessee Hollow, a remnant riparian corridor and a drainage way for the 31-acre Tennessee Hollow watershed; it runs along the western edge of the Letterman Complex.  The third significant natural landscape component is the coast live oaks, palms, redwood and eucalyptus trees which occur in existing open space areas, and the fourth is the wildlife habitat which occurs in association with these trees.  The natural landscape guidelines are intended to identify the site’s important natural features and provide direction for appropriate design strategies.

3.2.1  Design Principles

n  Respect and design with natural processes, systems and features—topography and soils, storm drainage, existing vegetation and wildlife habitat zones—at both the larger urban, and the more site-specific scale.

n  Employ sustainable and energy efficient site design, construction and maintenance practices.

n  Establish Best Management Practices for all natural landscape features and areas.

3.2.2  Guidelines

A. Topography and Soils

n  The change in elevation across the site in the north/south directions is approximately 55 feet. New development should respect and avoid alterations to this constant northward slope of the topography. Large-scale earthwork for foundations or underground structures should return the surface configuration to existing site contours.  Landscape terracing is to be avoided.

n   Although soils have been modified by water diversion, landfilling and construction, new development presents an opportunity to re-establish the quality of this resource. Enhance soil structure and fertility in all proposed planting areas and ensure that soil erosion and compaction is prevented during construction activity.

B. Storm Drainage

n   Due to the topographic slope and direct connection to the bay, the quality and quantity of storm-water drainage is an important consideration for any new development.  Incorporate the recommendations of the draft Presidio Storm Water Management Plan in the earliest design phases of new development.


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Figure 12.  Natural Landscape Elements


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Figure 13.  Critical Elements of Natural and Cultural Landscape


n  Consider future restoration opportunities for the Tennessee Hollow natural riparian corridor and linkage to the new wetland restoration at Crissy Field.  Investigate the use of Tennessee Hollow for discharge of surface runoff from western portions of the Letterman Complex.

n   Implement Best Management Practices during the design or re-design of storm-water drainage systems that discharge into riparian and wetland restoration areas to reduce potential impacts on water quality that could adversely affect aquatic and terrestrial habitat. 

n  Investigate the construction of surface collection and onsite infiltration systems for storm-water management.

Vegetation

The designed landscape of the Letterman Complex provides a rich cultural context and a unique sense of place that sharply contrasts with the Presidio’s forests and native plant communities.  Ornamental plantings played a significant role in the design of this landscape and the functional evolution of the developed site.  Fragments of the Letterman Complex’s vegetation planted during the period of historically significant development still remain.  These plantings, which have been present for 50 years or more, reinforce the role of the Letterman Complex landscape as an essential component of the National Historic Landmark designation.  These plantings also contrast sharply with the landscape within the 23-acre LAMC and LAIR site, which represents a significant departure from the complex’s original design intent and contains plants with strikingly different characteristics from historic species.  The following broad objectives should guide the management of the Letterman Complex’s designed landscape vegetation:

n   Design and site new landscaping elements in keeping with the historic character-defining elements of the Letterman Complex while allowing changes to occur that will encourage vitality of the site.

n   Retain the existing historic plantings and plant species, including all palm trees and the blue gum eucalyptus within the historic windrows, but avoid colonization of the eucalyptus through proper maintenance and management.

n   Retain native plant species that currently occur along Lombard Street and in the existing open space areas along Letterman Drive, including all coast live oaks trees.

n   Manage the health, vigor, and configuration of all species to be retained by following established horticultural and maintenance practices.

n   Replace exotic and ornamental species as necessary with trees that have been identified in the draft Vegetation Management Plan as being suitable to supplement historically planted species.  Ensure that the landscape plan utilizes the approved plant lists.

n   Consider historic plant use and design intent, function, and potential impacts to native plants when selecting appropriate plant material for replacement vegetation.

n   Acknowledge restoration and reconstruction of natural features as such; however, do not attempt treatments that try to recreate the appearance of an environment free of human intervention and use.

n   Minimize the development of a landscape that requires intensive ongoing maintenance and energy expenditures.  Plants should be disease- and pest-resistant, water efficient or drought tolerant, adapted to the site’s microclimate, and require minimal ongoing maintenance.  Plants that require intensive maintenance such as frequent pruning and irrigation should be carefully considered before planting.  Plants should also have the ability to withstand heavy recreational use and foot traffic.

n   Minimize storm-water runoff by maximizing groundwater percolation and storm water drainage.

D. Wildlife Habitat

The wildlife habitat areas that have been identified within the Letterman Complex are important primarily as nesting areas for migratory birds.  Although these areas are fragmented and isolated and do not provide as much resource value as contiguous habitat areas, they should be retained.  They are of relatively high habitat value despite their limitations because habitat is so scarce in the urbanized city of San Francisco.  The mature coast live oaks and palm trees in the existing open space areas are especially valuable.

n   Protect and enhance designated wildlife habitat areas (coast live oaks and palms) through management treatments and practices such as restricting the size of the work area, establishing appropriate buffer zones, avoiding work when soils are wet and prone to compaction, and careful training of work crews to reduce potential impacts on soils and vegetation. 

n   Ensure protection of nesting birds during construction and employ Integrated Pest Management practices in design solutions.

n   Direct storm-water drainage as appropriate to allow and enhance the future habitat restoration proposed for Tennessee Hollow and the Crissy Field wetland.  Ensure water quality is adequate to support habitat.


3.3 Planning Guidelines:  Cultural Landscape

The cultural landscape guidelines deal with issues that relate to the human occupation and transformation of land over time.  The new programs proposed for the Presidio are a continuation of the long history of human use and intervention in the area.  Since the eighteenth century, the Presidio’s natural landscape and form of the site has evolved and changed because of human activity; remnants of this process include infrastructure, buildings, and designed open spaces in which occupants transformed vegetation, drainage, and topography. 

In the 1996 publication, The Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for the Treatment of Cultural Landscapes (NPS 1996), landscapes like the Presidio are designated to be cultural landscapes. This is defined as:  “geographical area[s] (including both cultural and natural resources and wildlife or domestic animals therein) associated with a historic event, activity, or person or exhibiting other cultural or aesthetic values.”  The Presidio can be described more specifically as a historic designed landscape, which is “consciously designed or laid out by a landscape architect, master gardener, architect, engineer, or horticulturist according to design principles” and may display aesthetic values or be associated with significant practitioners, events, or trends in landscape architecture. 

The Letterman Complex includes traces and remnants of historic landscape features and components at a variety of scales: the historic Letterman Hospital complex; O’Reilly Avenue, Thornburg Road and Gorgas Avenue; the Presidio wall at Lyon Street and its associated windrow; the Lombard Street Gate, and sections of plantings which indicate the original alignment of Lombard Street. 

The Secretary’s Standards set forth guidelines for the rehabilitation of cultural landscapes on the premise that sites evolve over time, defining rehabilitation as “the act or process of making possible a compatible use for a property through repair, alterations, and additions while preserving those portions or features which convey its historical, cultural, or architectural values.”  The principle of rehabilitation is that new development should respect the historic character of the site without simply replicating it.  Extant and non-extant features of the cultural landscape should be used as a source of invention and inspiration, and significant existing features should be preserved and enhanced.  However, new designs should not attempt to reconstruct or imitate what existed previously in ways that are falsely historical or inappropriate for current uses. 

The redevelopment of the Letterman Complex provides the opportunity to invigorate and enrich a unique cultural landscape.  For further guidance in this process, consult both the Secretary of the Interior’s Standards for the Treatment of Historic Properties (NPS 1996).

3.3.1  Design Principles

n   The design of new and rehabilitated landscapes should acknowledge both extant and non-extant cultural landscape elements. Figures B-14 and B-15 indicate the significant contributing elements of the cultural landscape from the site’s period of significance.  They are shown in relation to important features of the natural landscape in Figure B-13.


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Figure 14.  Cultural Landscape Infrastructure


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Figure 15.  Cultural Landscape Elements

 


n   Future development at Letterman should take cues from aspects of the cultural landscape.  In particular, the future pattern of development should consider the layout of historic examples such as the historic hospital complex and the Panama-Pacific International Exposition when determining the orientation of streets and buildings, dimensions for block faces, and the locations of view corridors and a functional public open space network.  (See preceding section for a discussion of the historic evolution of the Letterman Complex.)

n   A fine-grained pattern of development is encouraged, with an emphasis on attractive and accessible, human-scale design, sensitive to the existing visual character of the Presidio.

n   Open, inviting, and accessible designs that orient primary buildings and entrances to public streets and open spaces are recommended.  Development patterns reminiscent of a gated” community or exclusive campus are strongly discouraged.

n   Opportunities should be sought that establish a development pattern that easily integrates with surrounding Presidio and city neighborhoods and positively responds to edge conditions.

3.3.2  Guidelines

A.     Landscape Framework

1.             Spatial Organization

The Army and the Panama-Pacific International Exposition represent the two major design forces at the Letterman Complex.  Spatial elements of their designs included: ornamental planting; historic open areas like the greensward along O’Reilly Avenue, fine-grained building complexes; walls and gates; an integrated system of streets; a system of surface runnels that drains the site.  These features should be considered in the planning and design of new facilities within the site.

2.             Topography and Drainage

n  Restore the existing historic Tennessee Hollow drainage on the site to flow into the Crissy Field wetland.  Future site plans and environmental analysis should include planning for restoration of the stream corridor, maintaining storm-water runoff water quality through bio-filtering, and ensuring a stream corridor buffer area.  The buffer width should be supported by information from technical experts.

n  Respect, and avoid alterations to, the constant northward slope of the topography.  Large-scale grading for foundations or underground structures should return the surface configuration to its historic slope and terracing should be avoided. 

n  Consider the use of a system of surface drainage channels with the scale and character of the historic runnel system for the removal of storm-water runoff.

n  Avoid excess pavement, particularly in close proximity to the Tennessee Hollow riparian corridor.

3.             Vegetation

n    Planting should be considered as part of the built structure of the new Letterman Complex.  The choice of plant material should be consistent with the goals and objectives of the draft Vegetation Management Plan and approved plant lists developed by the Presidio Trust, and should complement the spatial organization and architecture of new development.

4.             Special Features

n    Water Features:  Consider the character of historic water features—small interior courtyard fountains and surface runnels—in the design of new water features, if any.

n    Site Structures, Furnishings and Elements: The guiding principles for the placement of site furnishings in all areas of the complex are respect for historical character and reduction of impact on the cultural landscape.

-       Significant features of the cultural landscape such as drainage structures, hedgerows, gardens, building footprints and walls should be used as a source of invention and inspiration.

-           The selection of site furnishings such as seating, lighting, and small-scale site structures should be coordinated with the Presidio Trust in order to maintain compatibility with park-wide site furnishing standards.

-           Landscape materials and furnishings should be handsome and durable.

-           Pavement (permeable and non-permeable) should meet ADA requirements and should be compatible in color and material with other adjacent pavement areas in the Presidio.

-       Walls, railings, and fences, if used, should be of a material and scale reflective of the existing palette in the Presidio.

-       Benches and trash receptacles may be located on the porches of buildings, at entrances, and along lawn edges and sidewalks.  In historically significant areas, they should be removable to avoid permanent impact. If possible, historical documentation should be used to inform siting decisions.

-       Picnic tables should not alter the appearance of historic buildings significantly.  They should be placed in secondary but accessible areas, for instance, in courtyards or behind or beside buildings, where they are convenient to employees but unobtrusive.

-       Bicycle racks should be placed outside of areas with a high degree of historic integrity.  Bicycle racks for visitors should be located near building entries.  Bicycle racks for employees may be grouped and should be located behind buildings, near service areas, or in car parking areas. If racks are not located on existing concrete or asphalt paving, they should be located on permeable paving such as gravel or crushed fines. 

-       The selection of site furnishings such as seating, lighting, and small-scale site features should be coordinated with the Presidio Trust in order to maintain compatibility with park-wide site furnishing standards.

B.     Pattern of Development

1.             Orientation of Streets and Buildings

The general orientation of streets and buildings on the 23 acres should be based on historic patterns of development. At the O’Reilly and city edges, the existing street grids of the remainder of the Letterman Complex and the adjacent city district should determine the pattern of new streets.  At the heart of the site, new development should be oriented towards designated view corridors. Figure 16 illustrates these patterns.

2.             Spatial Organization

The relationship of indoor and outdoor spaces in new development should consider lessons provided by historic built patterns.  In general, an approach where buildings are located along streets with courtyards and open spaces located in block interiors is preferred.  The outcome—a fine-grained texture of buildings and open spaces that respect the human scale—should be a defining characteristic of new development within the 23-acre site. Figure 17 illustrates a historic example of a human-scaled courtyard.

3.             Building Entrances

Building entrances should be oriented to major streets and open spaces as appropriate. Visually interesting and pedestrian-friendly ground floor uses and treatments should be provided.  Placement of primary building entrances facing public streets is encouraged.  Secondary entries may be provided through courtyards and alleys.


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Figure 16  Pattern of Development


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Figure 17.  Letterman Courtyard

 

 


3.4 Planning Guidelines: scenic views

Views into and out of the Presidio are constant reminders of its unique place in the geography of San Francisco and the bay.  From the Letterman Complex, the visibility of cultural monuments like the Golden Gate Bridge, the Palace of Fine Arts, and the San Francisco skyline locates the landscape in the framework of the city; the visibility of important natural features like the Presidio Ridge, the bay, and the Marin Headlands locates the site in the ecological systems of the region.  Close and distant views of the Letterman Complex from outside the Presidio provide both information about the site’s character as a natural and cultural area and cues about entry and access. 

New development should be sited and scaled to preserve and enhance scenic views from the complex; as in the past, street edges, interstitial spaces between buildings, and planting should be located to frame important sites.  New buildings and plantings should also direct views into the complex from its edges and preserve views into and beyond the complex from adjacent neighborhoods at higher elevations.

3.4.1  Design Principles

n  Preserve and enhance scenic views and historic vistas from the Letterman Complex to surrounding visual landmarks including the Golden Gate Bridge, the city skyline, the bay, the Presidio Ridge, and the Palace of Fine Arts.

n  Preserve and enhance scenic views and historic vistas into and out of the historic hospital complex to the new redevelopment site to create visual linkages that tie together the 60-acre site.

n  Create opportunities for interesting landmarks and framed views into the Letterman Complex from its edges.

n  Protect the regional visual character of the Presidio as seen from surrounding residential areas.

3.4.2  Guidelines

A. View Corridors

n   Preserve and enhance important public view corridors indicated in Figure 18.  Extend the Thornburg Road view corridor to maintain and enhance its distant views towards the Golden Gate Bridge and the San Francisco skyline.  Frame views on axis with Letterman Drive to the city and Presidio Ridge.  Also, create a minimum of two view corridors within the 23-acre site oriented towards the Palace of Fine Arts.

B. Views into the Site

n   The most significant views into the Letterman Complex from its edges are from the Lombard Street Gate entrance and from the entry at Richardson Avenue.  It is recommended that views from these locations be framed and sensitively designed to provide an inviting glimpse of the site.  These views may be focused on a significant structure or landscape feature, or be left open to reveal a vista through the site.  The objective is to attract visitors and provide site identity for passers-by.


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Figure 18.  Scenic Views


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Figure 19.  Thornburg

Figure 20 Palace of Fine Arts

 

 


C. Viewsheds

n   Recognize that surrounding residential neighborhood located at higher elevations within the Presidio and the city look down into and across the Letterman Complex.  Be sensitive to this panoramic viewshed and create an attractively designed roofscape for the new complex.


3.5 Planning and Design Guidelines:  Building Form

Excellence in design for new construction project is a primary goal. While suitable for contemporary use, new construction should also be compatible with the historic setting through sensitive treatments of such elements as height, massing, scale, materials, and color.  The fundamental character-defining features of existing historic buildings at the Letterman Complex, identified in Section 2.5, Architectural Characteristics of the Letterman Complex, should be considered, and to the extent possible, should inform the architectural character of new development.  At the same time, the buildings in their expression must serve as a bridge between the Presidio’s past and its future.

The design philosophy reflected here is intended to provide a framework for building within the historic landmark district and the national park setting of the Presidio. The guidelines that follow provide general direction about site planning as well as specific recommendations for edge treatments, height, massing, scale, fenestration, building material and color palette, style, and sustainable design practices.  

3.5.1  Design Principles

n   Complement the existing historic fabric and respect the site’s National Historic Landmark setting in all new construction within the 23-acre site.

n   Promote architectural excellence through sensitive and distinguished contextual design.

n   Encourage new development to be compatible with the scale, architectural character, and pedestrian-friendly quality of existing historic buildings through sensitive use of color, texture, materials, fenestration, and building articulation and height.

n   Promote environmentally sensitive and energy-efficient building design that helps achieve the Presidio’s goal of being a model of sustainability.

n   Maintain and accentuate the natural topography of the site.

3.5.2  Guidelines

A. site planning

n   Overall built form should step down towards the north, respecting the natural topography of the site.

n   Site layout and building clusters should respect historic patterns of spatial organization and be compatible in scale with existing historic buildings.  Figures 21 and 22 illustrate these historic patterns. A fine-grained texture of buildings is desired, incorporating courtyard forms and human-scaled building masses.

n   A campus-like approach that integrates buildings and open space as a single ensemble is encouraged, specifically in the 23-acre site near the Lombard gate.  New buildings on this site as well as infill construction in the balance of the Letterman Complex should complement historic patterns of development.

n   Permeability, transparency, clear public access, aspect and prospect—all are encouraged as underlying principles in site planning and design.  To this end, provide view corridors, clear pedestrian routes through


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                Figure 21

n        Figure 22


n   the site, and ample opportunities for the use and enjoyment of public areas within buildings and in open space.

B. Edge Conditions

New construction should respect the character of existing natural and built edge conditions.  Significant edges and recommended strategies are outlined below.  Refer to Figure 23.

Along Lombard Street/Letterman Drive

n   This is the “formal” front door to the Presidio.  This edge of the site should present a gracious and welcoming face to Presidio visitors and evoke the park’s unique setting.  Locating buildings so as to hold the street edge and form a dignified façade to the new complex, visible to visitors entering and proceeding along Lombard Street is encouraged (see Figure 23). Publicly accessible uses on the ground floor, significant building entries, and careful massing and framing of view corridors to the Palace of Fine Arts should define the character of this edge.

Along Gorgas Avenue

n   As the primary vehicular entrance into the Letterman Complex, this edge is expected to be active and urban. As one of the few remaining industrial streetscapes in the Letterman Complex, this edge should also retain an architectural character that is simple and functional. This area would provide a first glimpse of the new 23-acre development for visitors and users of the complex.  Buildings along this street should thus accommodate a variety of inviting public uses, be built to street edges where possible, and have entries facing the street. The scale and architectural character of new buildings along Gorgas Avenue should relate to the austere, functional character of existing buildings.

Along O’Reilly Common

n   Provide a building edge which gives definition to the eastern side of O’Reilly Commons.  Encourage public uses on the ground floor, with frequent opportunities to enter buildings. An average distance of 125 feet should be maintained between the face of the historic structures on O’Reilly Avenue and the face of the new construction. The character of new buildings in this zone should provide a transition from historic to new—a counterpoint to the historic O’Reilly houses across the commons.

Along Lyon Street

n   Maintain and enhance the historic wall along this edge. Buildings should be set back from the wall by at least 30 feet of green space that serves as a buffer.  Rehabilitation and additional planting of trees to enhance the existing row of trees is encouraged.  Consider breaching the wall on axis with Chestnut Street to reintroduce this historic pedestrian connection into the complex.  Buildings along this edge should be compatible in scale with the residential character of buildings along Lyon Street.

Along Tennessee Hollow

n   Establish an easement along Tennessee Hollow for future restoration of the unique natural character of the riparian corridor.  Any landscape or site improvements planned for this zone should be set back from this


 

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n   Figure 23.  Edge Conditions

 


n   Placeholder for

n        Figure 24

n        Figure 25

                Figure 26


n   easement and should be low in scale and intensity, and compatible with the pedestrian-oriented character of the corridor.

C. Height, massing, and scale

n   Allowable maximum building height varies in the two parts of the 23-acre site, as shown in Figure 27. It shall be 60 feet south of Edie Road (Zone A).  To the north of Edie Road the maximum height shall be 45 feet.  Building height is measured from the finished grade to the top the of building. The top of the building is
defined as the finished roof in case of flat roofs or the top of a parapet, whichever is greater, and the average height of the roof rise in the case of pitched or stepped roofs.  On a sloping site, this measurement is taken at the median grade height of each building segment or face. Total individual building height is calculated by determining the average height of all individual building faces.

n   Monolithic structures with long, unmodulated facades should be avoided.  Building elevations should be articulated with setbacks and/or changes in height to break up the effects of continuous building walls.  Breaks or passageways should be provided to encourage and invite public access and pedestrian movement through and around the site.

n   Provision of unobstructed and expansive vistas into public areas, particularly within the 23-acre site is critical.  These include views in from Letterman Drive and from O'Reilly Avenue particularly on axis with Chestnut Street and Thornburg Road.

n   Building massing and siting should accentuate views, especially along designated view corridors.

n   Scale and dimensions of new buildings must respond sensitively to the scale of the existing buildings.

n   Efforts should be made to minimize the perception of building height; strategies include the creation of “attic stories” and roof dormers.

n   Rooflines should be simple and direct, emphasizing the horizontality of the buildings.  In general, shaped roofs are preferable to flat roofs.

n   As the roofs of Letterman Complex buildings would be visible from higher surrounding areas, they should be visually pleasing and use compatible colors. Mechanical equipment on the roof should be designed as a component of the building and not appear to be an add-on element.

n   Design of new buildings should be compatible with the surrounding residential neighborhoods and historic buildings.  They should be informed by the character-defining features of existing historic buildings.  Some of these elements include:

-      Simple, functional building character.

-      Complexes formed by smaller buildings connected with covered breezeways.

-      Buildings clustered around courtyards and intimate outdoor spaces.

-      Windows placed in a rhythmic pattern on building elevations.

-      Basement stories that are visible and at grade on the down-slope side of most buildings.

-          Projecting eaves and other architectural details that create horizontal shadows and accommodate decorative architectural elements.


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D. FENESTRATION

 Windows are character-defining architectural elements.  Shape, scale, proportion, rhythm, groupings, relationship to plan, relationship to exterior wall planes—all these are the architects’ tools used to develop a building’s appearance.  Designed with creativity and sensitivity, building fenestration will strongly influence the character of new buildings in the Letterman Complex.  Large-scale windows at entries and public areas will reinforce activity and vitality at the ground level.

n   To give building facades scale and dimension, variations in plane achieved by recessing windows are encouraged.

n   Refer to existing fenestration patterns used at the Presidio as precedents for design.

n   At the pedestrian level, every attempt should be made to create storefronts, public spaces and entry lobbies that are as open, interactive and interesting as possible.

n   All accessible windows should be operable.

E.  Building Material and Color Palette

n   The color palette for the exterior of new construction should complement the range of colors predominant in the Presidio.

n   Approved Exterior Materials: The prescribed list of exterior materials is based on character, durability, low-maintenance, and compatibility with the Presidio context:

       Stone

       Brick: may be painted

       Steel: steel windows, steel exterior doors, steel rails and fences; dull-finished stainless steel and painted are acceptable

       Aluminum:  windows, storefront, curtainwall, doors; aluminum to be powder-coated or kynar; reflective surfaces are not permitted

       Wood: siding, windows, doors, painted

       Glass (windows only): clear, low-e; shadow boxes, spandrel glass and obscure glass is permitted in limited quantities

      Painted cast-in-place concrete

      Painted galvanized flashing/gutters

       Ceramic tile as ornament or in small areas

       Cement plaster

       Roofing and flashing: copper, zinc, terne-coated copper, ternemetal, clay tile, slate, concrete tile, painted, galvanized metal.

 

n   Prohibited Exterior Materials: The following is a list of materials not allowed to be used:

       Plywood panels or unpainted wood surfaces

       Reflective metal finishes

       Dry-vit or EFIS

       Reflective glass


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Figure 28

        Figure 29

        Figure 30

        Figure 31


 

F.  Style

It is not the intention for all of the new architecture in the Presidio to reflect a singular style, or to appear as though one architect had designed it.  Instead, the goal is to establish a distinctive and diverse architectural vocabulary and a harmonious style that reference the Presidio’s existing fabric.  These principles are clearly mirrored in the Presidio's architecturally diverse building clusters, such as Fort Scott, Main Post, or the historic Letterman hospital.

n   The architectural expression of new construction should refer to the formal qualities of its immediate Presidio neighbors, rather than to the prototypes found in large-scale contemporary suburban developments.

n   New buildings should employ high quality building materials and a well-designed, carefully crafted vocabulary.

g. Sustainability

n   A primary Presidio-wide goal is the promotion of sustainable building practices.  Climate-responsive design that exploits the benefits of daylight and fresh air through site and plan layout, orientation, careful placement of windows and skylights, and strategic use of vegetation is encouraged.

n   In addition, building design and techniques that conserve energy and water, use environmentally responsible and recycled materials, reduce waste, and promote healthy environments are strongly encouraged.  For guidance on sustainable approaches, two references will apply. For rehabilitation of existing historic structures in the hospital complex within the 60-acre Letterman Complex, refer to the draft Green Building Guidelines for the Presidio of San Francisco (Presidio Trust 1999).  For new construction located on the 23-acre site, the U.S. Green Building Council’s Leadership in Environmentally Efficient Design (LEED) guidelines and rating system will be used by the Trust for evaluating building performance.  A LEED performance level would be established by the Presidio Trust prior to the building design phase.

n    Buildings should be designed with potential for interior flexibility to permit future modifications and reprogramming.

n   Landscape design should employ sustainable ecological principles to promote energy conservation, water management and habitat diversity.  Site and landscape design criteria outlined in the LEED Rating System will be employed in the evaluation of new development proposals

 

 


3.6 Planning Guidelines:  Access, Circulation,
and Parking

With its adjacent highway access and proximity to major San Francisco streets, the Letterman Complex is one of the most accessible sites within the Presidio.  One of the key transportation objectives for the Letterman Complex is to decrease dependency on the automobile and encourage alternative modes.  By virtue of its location and density, the Letterman Complex is ideally suited to promote this goal by enhancing pedestrian and bicycle connections, and improving transit access.  In addition, safe and efficient traffic flow could be readily achieved through better integration of the complex with local and regional systems.  The following guidelines offer recommendations to achieve these goals.

3.6.1  Design Principles

n   Serve the mix of uses at the Letterman Complex with a range of transportation modes consistent with Presidio-wide transportation strategies.

n   Develop a transition from the informal design of the Presidio’s primary road system to a more typical urban street system within the existing Letterman Complex.

n   Make pedestrian and bicycle connections within and beyond the Letterman Complex and link with local/regional streets, trails and destinations.  Enhance pedestrian and bicycle travel and safety in this area.

n   Promote transportation strategies that decrease dependence on automobiles and facilitate transit use.

n   Promote energy-efficient and sustainable transportation practices—promote a strong jobs/housing balance, encourage use of alternative modes of transportation, and institute Transportation Demand Management policies.

n   Minimize the effect of Presidio traffic on surrounding neighborhoods and discourage offsite parking.

n   Minimize the effect of traffic related to the 23-acre development on the smaller historic roads in the Letterman complex such as Torney, O’Reilly, and General Kennedy avenues.

3.6.2  Guidelines

A. Site Access

n   The entrance from the Lombard Street Gate should retain its historic importance as a primary vehicular entrance into the Presidio as a whole and for people on foot, bicycle, or public transit.  The new entrance from Gorgas Avenue should serve as the primary vehicular entry into the Letterman Complex (see Figure B-20).

B. Pedestrian, Bicycle, and Vehicular Access

n   Establish a clearly defined hierarchy of circulation routes within and to the site, as represented by the following categories:

Regional Highway Access Doyle Drive and Richardson Avenue

Primary Vehicular Streets Gorgas Avenue, Lombard Street/Letterman Drive, Halleck Street


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Figure 32.  Vehicular Circulation


Internal Circulation (vehicular and/or pedestrian) Thornburg Road, Girard Road, General Kennedy Avenue, Torney Avenue, O’Reilly Avenue, and new streets within the 23-acre site

Bike and/or Pedestrian Trails Tennessee Hollow future trail, O’Reilly Avenue, pedestrian path at Chestnut Street, Gorgas Avenue, Lombard Street/Letterman Drive, and Thornburg Road.

n   Encourage a rich pedestrian character within the Letterman Complex and encourage user-friendly access to surrounding Presidio and city destinations.  For generalized locations of pedestrian and bike connections, refer to Figures B-21 and B-22. 

n   Consider re-establishing a pedestrian entrance on axis with Chestnut Street, along the historic Lyon Street wall.

n   Use design elements such as gradient, width, surface, and edge treatment and materials as a means to differentiate circulation elements including pedestrian, bicycle, vehicular, parking and service areas.

n   Sidewalks and pathways should be appropriately lit, and streetscape elements such as paving, plantings, benches, trash cans, tree grates, kiosks, bike racks, etc., should be provided and be consistent with plans for Presidio-wide improvements.

C. Transit Access

n   Current bus stops and MUNI and Golden Gate Transit routes that serve the site are indicated in Figure B-23.  Consider integration of this transit network in new designs for the area.  Coordinate with the Presidio Trust towards developing better transit access, convenient new stops, and an internal Presidio shuttle route.

n   Acknowledge the potential for future water transit service at Crissy Field and allow for connections to it in new designs for the site.

n   Encourage innovations in transit and develop strong Transportation Demand Management policies in order to encourage transit use and decrease dependence on the automobile.

D. Parking

n   Remove and reconfigure existing large surface parking lots. 

n   Creation of large surface parking lots is strongly discouraged. Where surface parking is provided, landscape treatment should provide a visual buffer at the edges and frequent relief of green space and shade within the parking areas.

n   Underground parking lots (with careful consideration of archeological resources) and parking structures that are adequately shielded from public view are preferred. 

n   Street parking is encouraged, particularly in the public-use focus areas, for short-term parking.

n   Designated bus parking should be provided in a convenient location that is integrated into Presidio-wide transit and shuttle routes, and does not create barriers to pedestrian enjoyment or interfere with significant views.

n   Consider minimizing stormwater drainage and management through appropriate design and use of surface materials in parking lots.

E.  Signage and Wayfinding

n   New signage—public, residential, and business-related—should provide adequate information and direction to visitors while retaining the visual character of the historic district and maintaining consistency throughout the Presidio.

n   The design and placement of all tenant signs should be coordinated with the Presidio Trust to ensure compatibility with Presidio-wide sign standards.


 

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Figure 33  Pedestrian Circulation


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Figure 34.  Current Bicycle Circulation


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Figure 35.  Current Transit


 

The Planning and Design Guidelines are the basis for Design Review and form the main criteria against which the design will be evaluated.  Compatibility with the historic setting and design excellence are significant objectives identified in the Planning and Design Guidelines which will be considered during design review.

 

Participants in the Review Process:

·   The Presidio Trust Board of Directors or its delegates retain responsibility for initial review and final approval of the site plan, concept and schematic design, and are responsible for designating the design review team.

·   The design review team, consisting of 3 to 5 design professionals in the field of architecture and landscape design, will convene for specific review for all stages of the process. 

·   The Presidio Trust Executive Director is responsible for staffing of the review process by Trust staff and consultants and recommending designs for the Board to approve at the Concept and Schematic Design stages.

·   The historic compliance review team consists of the California State Historic Preservation Officer (SHPO), the Advisory Council on Historic Preservation (the Council), and the National Park Service (NPS), working in consultation with the Presidio Trust. Their role is to review the project at the conceptual and the schematic phase to ensure that the requirements of Section 106 and 110f of the National Historic Preservation Act are met, and that the objectives of the Planning and Design Guidelines are fulfilled.

·  The project proponent, consisting of the project sponsor and design team, including architect, landscape architect, and engineering consultants, will work with all other design review parties in the successful completion of the project.

The Design Review Process:

The Design Review process is a step-by-step process with each phase of review building on and refining the phase which came before it and consists of the following stages:

 

Orientation Session:

At the outset of the project, the project proponent team will meet with the Presidio Trust and the designated design review team to familiarize themselves with the project and design philosophy, to answer questions about the Planning and Design Guidelines, and to discuss the review process.

 

Site Plan Review

The design review team receives the materials submitted by the project proponent and works with them on site planning issues. The Presidio Trust Board reviews the submission and provides comments and direction.  Based on conditions established by the design review team, the Executive Director recommends its approval to the Board.

Conceptual Design:

The project proponent submits materials to the design review team and works with them on conceptual design issues.  The Presidio Trust Board reviews the submission and provides comment and direction.  The design review team then identifies conditions of approval and the Executive Director recommends these to the Presidio Trust Board.  The public is invited to comment on the conceptual design at this point.  The historic compliance review team reviews the conceptual design materials as well as the public comments that have been received, and consults with the Presidio Trust regarding their comments. The Presidio Trust takes into account the comments of the historic compliance review team, as well as public comments, and incorporates these into a conditional approval of conceptual design.

 

Schematic Design:

The project proponent submits materials to the design review team for initial review.  The Presidio Trust Board reviews the submission and provides comment and direction. The design review team identifies elements necessary for approval and the Executive Director recommends conditional approval to the Board.  The historic design review team also reviews the submission at this time and makes recommendations to the Presidio Trust Board who take into account these recommendations and conditionally approve the schematic design.

 

Design Development:

The project proponent submits materials to the design review team who reviews submissions, works with the proponent on Design Development issues, and approves design development for review by the Executive Director.  Consultation with the Board at this stage is planned only on an as-needed basis.

 

Construction Documents:

The project proponent submits materials to the design review team who reviews the submissions, works with the proponent on construction documents issues, and approves them for review by the Executive Director. The Executive Director reviews and approves the construction documents. Consultation with Presidio Trust Board at this stage is planned only on an as-needed basis. Finally, the submission is forwarded to the Presidio Trust permitting department which reviews and approves all construction and other required documents.

 

 


4. ADDITIONAL RESOURCES

Bio-Integral Resource Center 

          1996    IPM Action Plans for Pests at the Presidio of San Francisco.

 

Brack, Mark L., James P. Delgado, et al.

          1985    Presidio of San Francisco National Historic Landmark District, Historic American Buildings Survey Report.  

 

Haller, Stephen A.

          1994    “Letterman Hospital:  Work for the Sake of Mankind,” A Summary of Its Significance and Integrity.”        

 

Land and Community Associates

          1992    Cultural Landscape Analysis, Presidio of San Francisco.  Prepared for the National Park Service.

 

Langellier, John

          1996    El Presidio de San Francisco: A history under Spain and Mexico 1776-1846.

 

National Park Service, U.S. Department of Interior (NPS):

          1993    National Register of Historic Places Inventory—Nomination Form, Presidio of San Francisco.

 

          1994a  “Management of Cultural Landscapes” chapter in NPS-28: Cultural Resources Management Guidelines. Washington, D.C.

 

          1994b  Final General Management Plan Amendment and Environmental Impact Statement, Presidio of San Francisco, Golden Gate Recreation Area.

 

          1995    Guidelines for Rehabilitating Buildings at the Presidio of San Francisco. Prepared for the National Park Service by Architectural Resources Group (ARG).

 

          1996    The Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for the Treatment of Cultural Landscapes.

 

1997      Natural Resources Inventory and Vegetation Options, Presidio of San Francisco. Prepared by Jones and Stokes, Associates, Sacramento.

 

1999a Presidio of San Francisco Vegetation Management Plan and Environmental Assessment. In        cooperation with the Presidio Trust. Preliminary Draft 1999.

 

Presidio Trust

          1999    Draft Green Building Guidelines for the Presidio of San Francisco. San Francisco, CA.

 

Thompson, Erwin N.

          1995    Defender of the Gate: The Presidio of San Francisco, A History from 1846 to 1995. (Historic Resource Study). Volumes I and II.


5. GLOSSARY

Attic Story - Top story of a building located partially within the slope of a pitched roof.  Habitable attic stories may be used as a means to achieve lower building heights.

 

Building HeightThe vertical distance between finished grade and the top of a building.  Building top is defined as the top of the finished roof in the case of a flat roof, and the average height of the rise in the case of the pitched or stepped roof.  On a sloping site, this measurement is taken at the median grade height for each building segment or face.  Total building height is calculated by determining the average height of all individual building faces.

Campus-like Setting - A harmonious and unified setting achieved by the thoughtful placement of a group of buildings around grounds and open space.

 

Compatibility with historic setting - Maintaining the overall pattern of development and visual harmony in a historic area in terms of orientation, scale, texture, and architectural expression.

 

Contextual Design - New design that respects the existing context of buildings and landscape, and seeks to be a harmonious addition within this setting.

 

Cultural Landscape – The organization and interrelationships of the natural and designed features of a site by use reflecting cultural values and tradition, and changes to those features over time.  At the Presidio, this character is inextricably linked to its continuous military occupation since 1776.

Cultural Resources – An aspect of a cultural system that is valued by or significantly representative of a culture or that contains significant information about a culture.  A cultural resource may be a tangible entity or a cultural practice.  Tangible entities at the Presidio include archeological resources, cultural landscapes and historic structures.

Fenestration - The arrangement, proportioning, and design of doors and windows in a building.

 

Finished grade of site - Level of the final horizontal or sloping surface of a site that has been topped off with the intended finish such as grass, paving, concrete, or asphalt.

 

GreenswardA linear landscape element consisting primarily of lawn and planted trees which serves as an open space in a built-up or urban setting.

Historic Designed LandscapeOne that is consciously designed by a landscape architect, master gardener, architect or horticulturist according to established design principles.

Historic Character - The sum of all visual aspects, features, materials, and spaces associated with an area of historic importance.

 

Historic fabric - The physical remnants and materials belonging to a historic building,  group of buildings or landscape.

 

Modulated façade – Manipulation of the building’s exterior wall surface to create setbacks, projections, recesses, etc. which break up the plane of the wall surface.

 

National Historic Landmark (NHL) – These historic properties are designated by the Secretary of the Interior as having special importance in the interpretation and appreciation of the nation's history. Section 800.10 of the Advisory Council on Historic Preservation regulations specify some special protections for NHLs under the Section 106 review process.

National Historic Preservation Act (NHPA) – The basic legislation of the nation's historic preservation program that established the Advisory Council on Historic Preservation and the Section 106 review process.

Nonnative Plants – Plant species that have been introduced (or have invaded through natural dispersal from a site where they were introduced) and did not occur on that site prior to European settlement.  Even though a plant grows as a native species in a nearby location, if habitat for that species does not occur on the site and if it did not occur there as part of a native plant community, it is considered to be nonnative. (For example, coast redwood occurs naturally within the Bay Area, but it is considered nonnative to the Presidio.)

Panama Pacific International ExpositionAn exposition celebrating the opening of the Panama Canal, and the revival of San Francisco after the 1906 Earthquake. The Exposition was constructed by filling in marshland at the edge of the bay, creating the land area currently known as the Marina district, as well as the present day Crissy Field. It was open from February to December of 1915.

Permeability - In the context of built forms, the ability of a pedestrian to have frequent and clear physical and visual access through buildings and open spaces by means of streets, paths, and publicly accessible building interiors.

 

Period of SignificanceA defined period of time during which a property established its historical association, meaning, or value.

Presidio Trust – A federal government corporation established by Congress through enactment of the Presidio Trust Act (P.L. 104-333).  The Presidio Trust has two fundamental missions: preserve and enhance the Presidio as part of the national park system and achieve financial self-sufficiency by 2013.

Roof dormer - A roof that contains windows set vertically in a structure projecting through its sloping surface.

 

Spatial organization - The three-dimensional organization of physical forms in the landscape including the articulation of ground, vertical, and overhead planes that define and create spaces.  The design of streets, framing of views, placement of buildings etc. contribute towards spatial organization.

 

StreetscapeThe characteristics and components that give identity to a particular street.  This includes the street itself, the buildings that border it, its sidewalks, street trees, and site furniture.

Sustainability – An activity that meets the needs of the present without compromising the ability of future generations to meet their own needs.

Sustainable Design – An alternative approach to traditional design that does not require a loss in the quality of life, but require a change in mind-set and a change in values toward less consumptive lifestyles. These changes embrace global interdependence, environmental stewardship, social responsibility and economic viability.  Sustainable design recognizes the impacts of every design choice on the natural and cultural resources of the local, regional and global environments.

Transparency - In the context of built forms, the revealing of uses and spaces within and in between buildings, particularly on the ground floor, through the use of elements such as windows, storefronts, porches, and large public entries.

 

TreatmentA physical intervention, or development framework, carried out to achieve a historic preservation goal.  Treatment options include preservation, restoration, reconstruction and rehabilitation.

Viewshed – The geographic area from which a site is visible, a collection of viewpoints.

Wetlands Areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions.  Wetlands generally include swamps, marshes, bogs and similar areas.

Windrow (or Windbreak)A hedgerow or tight planting of trees made in open areas to protect a landscape or building from winds.


 

The Planning Guidelines are not intended to, nor do they create any right, substantive or procedural, enforceable at law or equity by a party against the Presidio Trust.  They should not be construed to create any right to judicial review involving their compliance or noncompliance, and variations from these Planning Guidelines should not give rise to any independent cause of action.