V. PLANNING PRINCIPLES And

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1 V. PLANNING PRINCIPLES And Urban Design Framework

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3 V. Planning Principles And Urban Design Framework Overview The responds to the planning parameters and the development potential framework established in the existing conditions. The principles that follow are the first steps toward a physical plan. They represent the broad physical design objectives which can be applied to subsequent concepts developed for the site, with an overall purpose of integrating new construction with existing historic buildings and landscapes and the natural environment. The aim is to realize the protection, enhancement and continuous improvements of historic building and landscape features that are distinctive elements of the site. Moreover the principles aid the master plan in establishing urban design goals that will guide subsequent redevelopment. The description of the site continues to use the five parcels as reference points. Site Parcels Principle: Respect the individual and unique character and history of each site parcel in making redevelopment decisions. Site Parcel 1 contains the most significant views towards Washington, D.C. and Virginia, housing the majority of buildings in the historic core including the Center Building, which acts as a focal point for the campus. It also contains the primary gateway to the campus along Martin Luther King Jr. Avenue. Site Parcel 2 includes the southern formal open space surrounded by buildings 64, 67, 68, 69, 72, 73, 74 and 75 which are some of the most important historic structures on the site. Site Parcel 3 contains the Greenhouses on the upper plateau and a few residences along its steeply-sloped forested areas. Site Parcel 4 includes the Warehouse and Power House buildings. The Power House stacks can be seen from various regional points beyond the campus. Site Parcel 5 is heavily forested in steep slopes and contains the Cemetery. Figure 5.1 Planning Site Parcels Planning Principles 59

4 Campus Structure and Organization Principle: Retain, preserve and enhance site elements and spaces that define the existing site character. The major character giving elements of the existing campus are combinations of existing buildings, landscape elements, landscape types, circulation paths, and views. Considering that the character of the site is perceived primarily from only those locations entirely on or immediately adjacent to the site, the principle of retaining and enhancing that character must address the campus as experienced from those vantage points. Plateau Area - The major character-defining element of the campus is its core area, the combination of relatively small red brick buildings arranged around an informal landscape of open lawns with individual and small groupings of trees, fountains and summer houses. This character is continuous from the Site Parcel 3 and the Point, through Site Parcel 1. It connects through to the Site Parcel 2 and the great lawn with its strong building assembly on its east edge and also to the more open meandering plateau-edge buildings on the west and south. Related to this major character-giving element, the individual open spaces each provide a key element to the respective parcels. Site Parcel 1 buildings enclose smaller outdoor spaces that relate back to the major core areas by way of passages between and among buildings providing a change in scale and activity away from the central areas. Similarly there are areas along the plateau edge that are somewhat removed from the central core and are more passive areas that transition from the core to the wooded slopes that make up the western edge of the campus. Sloped Area - The wooded western slopes, particularly on Site Parcel 5 and the majority of Site Parcel 3, are strong character-giving elements. These slopes and the roadways and pathways through them provide an enclosed, shaded environment, isolated from the other areas and activities of the campus. The restoration and maintenance of these wooded areas can offer that distinct experience to campus employees. A similar environment surrounding the Cemetery is a unique character-giving element, providing that setting with its own quiet, respectful character. Gates - The wall and gates on Martin Luther King Avenue are the most externally visible character-giving element for the campus. This assemblage is to be preserved to the greatest extent practicable. In particular, the Gate 1 portion, together with the gate house and landscape between the gate and the Center Building, form the essential formal entry sequence to the campus. The sense of the historic landscape setting should be preserved as part of that entry experience. 60 Planning Principles Upper Plateau Proposed Building Frontage Expansion Proposed Grid Expansion Steep Slopes (Topographic Bowl) Areas of Intervention Figure 5.2 Campus Structure and Organization The Point Center Building tower Cemetery

5 Development Density Principle: Locate new development density on site to respect the character of and relationships between the historic resources. The establishes three density zones in order to maximize development of the campus while respecting the character of the existing site and the basic relationship of the existing historic resources to the maximum extent practicable. Zone I Higher Density Any major development should be located in this zone which can accommodate taller structures and bigger footprints than the remaining zones. up to 8 floors. Zone II Medium Density Historic Core any additional development in this zone should be placed taking into consideration the character of the historic buildings and landscape. up to 6 floors. Zone III Lower Density With steep slopes and forested areas this zone will work as a buffer area between the campus and adjacent residential communities, while maintaining their regional character as a portion of the topographic bowl. up to 4 floors. Though urban areas can be dense without tall buildings, height does have an impact on density. The 2006 Comprehensive Plan for the National Capital contains recommendations for densities within the St. Elizabeths Campus. Policy FSS-2.2.4, from the July 2006 Mayor s Draft of the Comprehensive Plan for the National Capital, recommends that new construction should provide development densities and intensities on the site that are compatible with adjacent residential neighborhoods with moderate to medium density residential and commercial on most of the site, with higher densities clustered in the area closest to the Metrorail station. The Comprehensive Plan for the National Capital allows a maximum of eight stories for medium density commercial development that differs from the uses of the Saint Elizabeths West Campus. I Higher Density II Medium Density III Lower Density Figure 5.3 Density Diagram Planning Principles 61

6 Planning Relationships Principle: Organize programmatic elements on site to maximize operational efficiency and effectiveness. A critical element of the site organization will be the creation of the appropriate links and adjacencies of program elements to each other. All program elements on site will be related to the campus center and the core shared uses, but the operational relationships among the major components is the critical planning principle for the Department s effectiveness in carrying out its mission. The campus center will act as the center of activities common to all the program elements located on the campus. This center will be the point at which personnel from all elements are provided the opportunity to meet, mix and form a common identity among the operational centers. This opportunity is key to transforming the culture of the many agencies into a single culture that is the Department of Homeland Security. Potential Administrative Reuse Proposed New Development Potential Campus Amenities Campus Center Service/Support Figure 5.4 Planning Relationships 62 Planning Principles

7 Historic and Visual Resources Building Reuse Principle: Protect, preserve and reuse the historic resources of the National Historic Landmark. A major planning principle and planning concept for the Master Plan is the preservation and reuse of the historic resources of this National Historic Landmark. Those resources consist of the historic contributing buildings, the historic landscape and landscape site features, and the ensemble of buildings and landscape that create the unique character of this site. The character of the site is intimately related to the historic evolution of mental health care that occurred here and the social context in which that evolution took place. To protect and preserve that character, the strives to retain and rehabilitate the historic structures to the maximum extent practicable and to preserve the various historic resources, including open space, landscape structures and groupings of buildings within that landscape. The seeks to maintain and reinforce the historic character, organization and sense of hierarchy of the central campus core and major building anchors and groupings. This includes recognizing, preserving and reinforcing the major place-making site features, such as the Center Building, The Point, the curvilinear road network, the central lawn of the south cottage area, and the surrounding green buffer on the north, west and south edges of the site. The Center Building is the oldest and most prominent building on site, its views out to the city and its central location are critical. The function of the main building should, if possible, be central to the function of the campus or the main tenant. In order to maintain the historic character of the site the best use must be found for each of the contributing buildings. To reuse and restore the historic structures to the greatest degree possible, an effort has been made to match new programmatic uses that are the same or similar to the originally designed use for each structure (e.g. auditorium conference; firehouse emergency vehicle storage; Power House central plant and cogeneration equipment). In most instances this is not possible and the original buildings will be converted to the new program of administrative and support spaces suitable to a federal government departmental headquarters. Buildings to Reuse Non-Reusable Buildings Figure 5.5 Historic Resources - Building Reuse Planning Principles 63

8 Historic and Visual Resources Landscape Principle: Integrate historic landscape and natural features into the master plan. The master plan considers the therapeutic, ornamental, agricultural, and service aspects of the hospital s historic landscape, as well as the individual features that constitute that landscape. The historic landscape and natural features in the campus will be integrated into the to the maximum extent practicable. Historic landscape patterns will link the various areas of the campus, enhancing views within the site. The Landscape Assessment Plan (Heritage Landscapes, 2005) divided these campus features into functional landscape units that correspond to the Site Parcels described below: Site Parcel 1: Therapeutic, Ornamental Landscape Center Building and Main Gate Site Parcel 2: Therapeutic, Ornamental Landscape Lettered Buildings and Secondary Entrances Site Parcel 3: Agricultural Landscape Fields and Greenhouses Site Parcel 4: Service Landscape Powerhouse Ravine and Service Buildings Site Parcel 5: Cemetery and Woodland Slopes Throughout these landscape units/site parcels are significant open spaces, such as the greenspace of The Point and that of the Site Parcel 2; clusters of buildings constructed to implement evolving therapeutic philosophies; circulation patterns developed over the hospital s history and the processional experiences these patterns influence; vegetative features, such as the oak allée adjacent to the Center Building; and man made features, including the summer houses in the Site Parcel 1, that embody the hospital s history. Boundary Line Existing Buildings Historic Woodlands Lawn Upper Plateau Cemetery Parcel Major Open Space 64 Planning Principles Therapeutic Ornamental Landscape & Overlook Therapeutic Ornamental Landscape around Pavilions & Secondary Entrances Agricultural Landscape of Fields & Greenhouses Services Landscape & Ravine around Powerhouse and Service Buildings Cemetery & Woodland Slopes Figure 5.6 Historic Resources - Landscape Source: St. Elizabeths Hospital Historic Resources Management Plan by Devrouax Purnell Architects, (1993); St. Elizabeths Hospital West Campus Landscape Assessment Plan by Heritage Landscapes, (2005)

9 Historic and Visual Resources Views Principle: Maintain and enhance historic views from and within the site, as well as valuable non-historic views from outside the site. Nonhistoric Views Views of the site from prominent locations of D.C. and Virginia, due to its privileged location on the Anacostia Hills (Topographic Bowl). NCPC and CFA have identified these views as valuable to the character of the city. Regional Views (views from surrounding areas towards the campus). All views are zoomed in and real distance is shown in the picture caption. Neighborhood Views (views from immediate neighborhood towards the site) Historic Views These visual resources are those envisioned by the designers of the hospital and consist of views outward from the site and views from within the site itself. Views from St. Elizabeths toward the Anacostia and Potomac rivers, Washington, D.C., and the Virginia shoreline Views of the campus buildings and landscapes available when walking or riding through the grounds Regional and Neighborhood Views The will maintain and enhance views toward the campus. The West Campus sits on a plateau in the Anacostia Hills portion of the Topographic Bowl, southeast of the Monumental Core of Washington, D.C. The site is visible from numerous locations around surrounding neighborhood and from the region, as it sits along the green ridge and slopes of the Anacostia Hills. Figures 5.7 and 5.8 emphasize the views from the site to three important landmarks in Washington, D.C.: National Cathedral, Washington Monument, and the U.S. Capitol Building. Figure 5.7 Viewshed Context Washington Monument National Cathedral Old Post Office U.S. Capitol Building Topographic Bowl Slopes and Rims Views Out of the Site Plateau Steep Slope Image relationship to original photograph Figure 5.8 Zoomed in view from the site towards Monumental Core of D.C. (2.85 miles from the Point to Washington Monument) Planning Principles 65

10 Views From and Within the Site The will maintain and enhance views from and within the west campus. To respect the presence and predominant character of the Center Building on the campus, all proposed buildings will be no taller than its tower at 256 above sea level (msl). Within the campus, numerous multidirectional significant views are found across and around the campus. These include views across the Site Parcel 2 open space surrounded by the historic buildings, views along the allée of trees toward the Center Building from Gate 1, views of the Center Building from the plateau to the north, views of the plateau to the north from the Center Building, and views within the central core area of the campus. SITE PARCEL 2 A Views Looking Towards the Site Adjacent Views Looking Towards the Site External Views from the Site Primary Internal Views Oak Allée Note: Throughout the site, other omnidirectional views exist A Section Cut Figure 5.9 Views Diagram Center Building tower Figure 5.10 Existing Conditions Section through Center Building Tower. 66 Planning Principles

11 Site Access and Circulation Access Principle: Respect and reinforce the historic address for the site on Martin Luther King Jr. Avenue. The main public frontage to the St. Elizabeths West Campus remains along Martin Luther King Jr. Avenue which will be the primary regional public address for the campus. The existing main campus entries, Gates 1 and 2, along the Avenue will be upgraded to serve the new demand while maintaining their historic character to the maximum extent possible Gate 3 will be an at-grade access point to the west campus. Additional ingress/egress access to the campus will be provided via a new road along the western portion of the site, between Firth Sterling Avenue and the Malcolm X ramp from. Public transportation vehicles, bicycles and pedestrians will have access to the campus from the same entry gates used by automobiles. Circulation Principle: Use historic roadways and paths to reinforce spatial continuity. Employees and visitors accessing the campus by automobile will be immediately directed to parking garages. Within the campus, vehicular circulation will be limited to fully screened vehicles only, primarily shuttle buses. The plan encourages the use of the existing campus roadways and campus loops to provide clear access to all areas of the campus and to act as an orienting device for employees and visitors. Major Vehicular Entry (Employee/Visitor) Proposed additional Vehicular Entry/Access Primary Public Access Current Campus Circulation Proposed Additional Campus Circulation Figure 5.11 Site Access and Circulation Planning Principles 67

12 Parking Principle: Locate parking at the site perimeter to preserve a pedestrian-oriented site, consistent with historic precedent. The strategy for distributing parking at the St. Elizabeths West Campus is to provide structured garages at the eastern and western perimeters of the campus. This allows the garages to be conveniently accessed from major existing and proposed roadways and entry points. Parking spaces will be allocated and distributed in relationship to the access roads employees will be using. Parking garages are permitted to be located within the 100 ft. setback from adjacent roadways. They will be located away from sensitive historic resources in the core of the campus. Any above-ground parking structures will be landscaped, screened and buffered from nearby residential neighborhoods. By locating the parking at the perimeter of the site, the dominant modes of circulation around the site will be on foot or via shuttle buses. Major Vehicular Entry Proposed Additional Vehicular Entry/Access Parking Access Road P Parking Figure 5.12 Parking Distribution 68 Planning Principles

13 Site Environment Principle: Develop landscape responses that respect the inherent distinctions between the different zones of the site. The site environmental framework must balance the demands of historic and cultural resource protection, environmental and sustainability goals, and the functional requirements of new construction and tenant specific needs. To do so, the environmental framework depicts 6 different zones that will require a different landscape response, from landscape and cultural resource protection on the plateau, to management and restoration of habitat on the western slopes. Different approaches to stormwater treatment and management, landscape preservation, and habitat restoration will be emphasized depending on the landscape zone. The zones and their principles include: 1 Historic/High Quality Woods Preserve the mature, high quality woodlots on ravines and steep slopes (1A, 1C), and within and surrounding the Cemetery (1B). Minimize any intrusion from construction and earthwork in this zone. Remove/ relocate storm sewer outlets from steep ravines wherever possible. Remove and manage invasive species within mature woodlots, per Habitat Restoration techniques below. 2 Historic Landscape, Views, and Open Space Maintain and preserve the historic and cultural landscape of the plateau. Stormwater management techniques must respect the character of the landscape in this zone. Respect the view corridors from the plateau, particularly the views from the northwest overlook, The Point. 3 Transition Zone of New Construction Some edges of the upland plateau are suitable for new development. Construction and earthwork pose opportunities for recreation of a landscape zone around proposed buildings. 1 Historic/High Quality Woods The landscape typology of these transition areas as wooded slopes should reflect the general landscape characteristics of the plateau (open lawn and shade trees), with opportunities for managing small stormwater events, and re-introduction of native plant material. 2 Historic Landscape, Views, and Open Space 3 Transition Zone of New Construction 4 Functional Landscape 5 Development on Western Slopes 6 Environmentally Sensitive Habitat Figure 5.13 Environmental Framework Planning Principles 69

14 Site Environment 4 Functional Landscape The northwest corner of the site, below the overlook, was historically a functional landscape of open farmland and crops. The area now is overgrown with poor quality woods and invasive species. Re-use the functional landscape and former agricultural fields for new functional purposes such as a wet meadow, to provide open views, different habitat, and stormwater management for the campus. 5 Development on Western Slopes The wooded western slope of the campus has contributed to the larger regional landscape pattern of the river basin. The bluffs overlooking the river form a wooded, green backdrop around the Capital region, as part of the topographic bowl surrounding the city. The demolition of large-scaled non-contributing buildings makes the western slope area one of high potential for new development. This area may require major earthwork and re-grading to accommodate development. Though the majority of the western slope is vegetated with invasive species and lower quality, successive growth from the past 30 years, it is critical to re-establish a wooded tree canopy on the slopes after construction. Re-forest slopes impacted from construction with native species to re-build habitat, slope stability, and the visual character of the region. 6 Environmentally Sensitive Habitat Unstable fill, potential soil contamination, and a bald eagle nesting site create a zone of no construction and no disturbance on the southwest side of the campus. Preserve and maintain this area free of any construction or intrusion. Site Habitat Principle: Restore the ecosystem potential of the West Campus environs allowing organisms within their biological communities to live and reproduce. Although the West Campus property has seen a long history of past use, this redevelopment presents an opportunity for habitat restoration along the banks of a major wildlife corridor, the Anacostia River. Taking into account the proposed program requirements, there still remains a great potential to improve the biotic characteristics of the site. These activities should focus primarily on ravine restoration and establishment of native vegetation. 70 Planning Principles Ravine Restoration The existing ravines are bounded by steep slopes fed by surface water runoff and direct stormwater discharge. Surficial erosion, channel scour and slope failures have created an unstable and eroded condition. Application of appropriate stabilization measures is critical to halt this condition. Techniques such as stepped pools, boulder cascades and stone weirs should be implemented to dissipate energy, lower channel velocities, increase channel roughness, trap sediment and provide a stable channel environment. Establishment of Native Vegetation Invasive and non-native plant species dominate the west slopes of the West Campus property. Such species provide little habitat for the organisms that could potentially inhabit this area. Removing these species is a key step in promoting a diversity of protective ground-layer vegetation and encouraging regeneration of native trees and shrubs. Reforestation of these slopes should be emphasized within the context of the proposed building program. This presents an opportunity to eliminate unwanted species, reintroduce native vegetation, increase slope stability through restoration of a root mat and restore soil structure and the biological properties associated with soil nutrient cycling. Optimize the Historic Functional Landscape Re-use the functional landscape and former agricultural fields for new functional purposes such as a wet meadow, to provide open views, different habitat, and stormwater management for the campus. Site Hydrology Principle: Accommodate new development while restoring site hydrology by maximizing pervious surfaces, managing rainfall where it falls, using surface water conveyance and seeking campus-wide opportunities. Maximize Pervious Surfaces Impervious surfaces due to new construction can be mitigated through the use of green roofs and pervious pavements. Both of these strategies are viewed as 100% pervious by city standards. Historic roofs are not suitable for green roofs; however modern flat roofs would be ideal Case Studies: Examples of pervious surfaces. for green roof applications. A goal of 50% green roofs on all new buildings should be considered as a minimum. Pervious pavements are ideal for roads and walks on relatively flat surfaces that do not need to accommodate heavy traffic and should be considered wherever these conditions exist. Manage as Close to the Source as Possible Runoff from impervious surfaces should be managed for water quality as close to where rain falls as possible in bio-retention cells. Infiltration should be encouraged. A minimum of the first half inch of rainfall should be managed for all events; however a more aggressive goal of 1.5 would allow buildings on the site to meet LEED credit 6.1 by managing over 90% of the average annual rainfall. Case Studies: Examples of managing close to the source. An analysis of the historic rainfall for Washington, D.C. illustrates that managing water quality for the 0.5 event will treat 66.7% of the average annual rainfall. However, managing the 1.5 event will treat 94.6% of the average annual rainfall and allow building projects to receive LEED credit SS 6.1, which requires 90% of the average annual rainfall to be managed (See table below). Utilize Surface Conveyance By moving water in shallow swales, water is slowed and cleaned, more closely mimicking pre-development times of concentration. This should be considered in varying strategies to fit within the historic character of the site. Case Studies: Examples of utilizing surface conveyance Case Studies: Examples of utilizing surface conveyance

15 Site Environment Green Buildings Principle: Orient and collect buildings into clusters to maximize their environmental effectiveness Orient buildings with their long axis in an east-to-west orientation to maximize their capacity to either collect solar benefit or shade unwelcome solar gain. Locate buildings so that spaces between them are of sufficient dimension to allow full solar access to all floors. Create compact collections of buildings to preserve large areas of contiguous habitat and a coherent network of public outdoor spaces. Use building locations and site elements to create micro-climates of sun, shade, breezes and shelter that extend the period of comfortable human occupation of exterior spaces. Case Studies: Examples of looking for campus wide opportunities Look for Campus Wide Opportunities While steep slopes and uncharacterized fills may make management of large events impractical, there may be opportunities to manage some water quantity events along the western edge of the plateau or along the western slopes of the site, particularly the northwest corner of the site. These facilities may take the form of wet meadows or stepped constructed wetlands to manage water quality and quantity for the site. Building Water Principle: Optimize the use of potable water primarily for uses related to human health. Case Studies: Examples of building water Potable water has become an increasingly valuable resource. Therefore the campus should strive to maximize its efforts to collect and reuse available water supplies on site. There are three main strategies that can be implemented to help achieve this goal. First, the implementation of low-flow or waterless fixtures in lavatories and water closets can have a significant impact on potable water demands. This can be achieved at a minimal initial cost over the cost of standard fixtures. Second, graywater collected from lavatories can be stored and made available for flushing toilets, potentially offsetting all potable water requirements. This strategy requires a dual plumbing infrastructure to allow graywater collection in a separate system. Additionally, a cistern, filtration and pump system are required to store and make graywater available for reuse. Third, stormwater can be collected from rooftops to be used in flushing toilets, potentially offsetting all potable water requirements. This strategy requires a rooftop collection system, filter, pump and cistern for storage and distribution to toilets. The cistern required for this strategy would be substantially larger than a graywater system would require due to the inconsistent nature of rain events. Case Studies: Examples of building water Planning Principles 71

16 Site Infrastructure Principle: Centralize site utilities for security, redundancy and operational efficiency. As a consolidated campus, the utility and support/service infrastructure is planned around the concept of central facilities for operational, security and maintenance functions. Efficiency of centralized functions will benefit all tenants and enhance energy efficiency and redundancy requirements. As a principle of design, GSA promotes energy efficiency and sustainable environmental design approaches. The includes those concepts and applies them to the overall campus infrastructure for both the energy demands of operating buildings and for the conservation of water, and the maintenance of water and air quality as it is affected by the development of the site. As a unified campus, the infrastructure for all utilities is planned to provide all services to match the requirements for each facility and to tie all facilities together. Utility support includes water (domestic water, storm and sewer), heating, cooling, electric power, communications and data systems. Principle: Consolidate site utilities and below-grade distribution to maximize the integrity of the historic landscape. To the greatest extent practicable, all systems will be circulated through the campus along common utility corridors. Common paths will limit the impact on the landscape and will create a limited number of access points required for service and maintenance of systems. Portions of the utility infrastructure will be distributed in tunnel structures and in some cases the tunnels will also be used for personnel movement. Communications infrastructure will also include satellite dishes and other antennas. These are to be located to insure correct function and to be screened from views both within and from without the campus. The basic heating, cooling and electric power portions of the utility system will be distributed between a central utility plant (CUP) location and the individual structures on site. The CUP location will also include a cogeneration facility that will serve to offset electrical demand on the public utility grid, provide power redundancy, and enhance the overall efficiency of power usage on campus. Major Underground Utility Corridor Primary Public Access Figure 5.14 Underground Utility Corridor 72 Planning Principles

17 Security Principle: Assure the safety and security of the site s occupants and activities while maintaining an appearance to the site that is open, accessible and a good neighbor. While the Department of Homeland Security requires a secure campus, the plan strives to retain, to the greatest degree possible, the appearance of an open, accessible place that is part of the public realm. The will be a secure campus for Federal agencies. Security on the site will consist of a secure perimeter that provides the necessary security envelope for all the tenants while allowing the site to operate with a minimum of internal controls and security personnel. The security fence system will be designed to prevent unauthorized entry along the entire perimeter. The security system and perimeter are planned to allow for the campus to operate normally under all but the most severe threat conditions. Normal operations accommodate the normal complement of employees and visitors to the site employing the same security operations and procedures as used during periods of low threat. To accomplish this, the secure perimeter is planned to include all necessary screening for both personnel and vehicles accessing the site. The basic security concept with regard to vehicles is to place all parking at the perimeter of the site so that parking areas are separated from all occupied facilities by required distances and that all personnel entering the site pass through check points that verify authorization for entry. The number of entries to site is kept to the minimum required to accommodate the number of vehicles and personnel arriving and departing the site. As part of the total secure perimeter a single point for screening of deliveries is to be provided. This screening facility will eliminate the need for direct delivery to individual buildings and will provide an efficient and secure method for screening all deliveries to the campus. Major Vehicular Entry & Exit Proposed Additional Vehicular Entry/Access Security Perimeter & 100 Stand-off Zone Employee/Visitor Screening D/S Employee Screening/Delivery Figure 5.15 Security Diagram Planning Principles 73

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