Safe School Design
The Federal Emergency Management Agency (FEMA) developed a Primer to Design Safe School Projects in Case of Terrorist Attacks in 2003. This Primer outlined threat and risk assessment for school buildings in the face of a terrorist attack, including car and truck bombs. Specifically, the Primer outlines comprehensive architectural and engineering design considerations (mitigation measures) for the school site, from the property line to the school building, including: land use, site planning, stand-off distance, controlled access zones, entry control and vehicular access, signage, parking, loading docks and service access, physical security lighting, and site utilities, to help reduce the risk and damage to a school building as a result of such an attack. Overall layout, stand-off zone, raodways and parking, and lanscape and urban design are just a few aspects of site design that should be taken into consideration when constructing a school in order to protect it from potential terrorist threat. For the complete Primer, click here
The overall layout of a school site (e.g., the placement and form of its buildings, infrastructures, and amenities) is the starting point for development. Choices made during this stage of the design process will steer decision-making for the other elements of the site. A number of aspects of site layout and building type present security considerations and are discussed below.
Clustered versus dispersed functions. There is a strong correlation between building functions and building layout and forms. Typically, the former dictates the other two. Depending on the site characteristics, the occupancy requirements, and other factors, school buildings may cluster key functions in one particular area or have these functions designed in a more dispersed manner. Both patterns have compelling strengths and weaknesses in terms of security. Concentrating key functions in one place may create a target rich environment and increase the risk of collateral impacts. Additionally, it increases the potential for the establishment of more single-point vulnerabilities. If these areas become a target, the school may be closed for a substantial period of time, even if the attack is not severe and the rest of the school remains unharmed.
However, grouping high-risk activities, concentrations of personnel, and critical functions into a cluster can help maximize stand-off from the perimeter and create a "defensible space." This also helps to reduce the number of access and surveillance points, and minimize the size of the perimeter needed to protect the school areas. In contrast, the dispersal of key functions reduces the risk that an attack on any one part of the site will impact the other parts. However, this could also have an isolating effect and reduce the effectiveness of on-site surveillance, increase the complexity of security systems and emergency response, and create a less defensible space.
School building orientation. The orientation of a school building can have significant impact on its performance, not only in terms of energy efficiency, but also the ability to protect occupants. A school building's orientation relative to its surroundings defines its relationship to that area. In aesthetic terms, a school building can open up to the area or turn its back; it can be inviting to those outside, or it can "hunker down" defensively. The physical positioning of a building relative to its surroundings may seem more subtle, but can be a greater determinant of this intangible quality than exterior aesthetics. Nevertheless, the proximity of a vulnerable façade to a parking area, street, adjacent site, or other area that is accessible to vehicles and/or difficult to observe can greatly contribute to its vulnerability. This illustrates one way in which protective requirements can be at odds with otherwise good design. A strong, blank wall with no glazing will help to protect students, faculty, staff, property, and operations within from a blast, but the lack of windows removes virtually all opportunity for the faculty and staff to monitor activities outside and take appropriate protective actions in a timely manner. Designers should consider such trade-offs early in the design process, in an effort to determine an acceptable level of risk.
Open space. The incorporation of open space into school site design presents a number of benefits. First and foremost is the ability to easily monitor an area and detect intruders, vehicles, and weapons. Closely related to this benefit is the stand-off value of open space; blast energy decreases as the inverse of the cube of the distance from the seat of the explosion, so every additional increment of distance provides increasingly more protection. In addition, pervious open space allows stormwater to percolate back into the ground, reducing the need for culverts, drainage pipes, manholes, and other covert site access and weapon concealment opportunities. Also, if the open space is impassible for vehicles (as in the case of a wetland or densely vegetated area), it can provide not only environmental and aesthetic amenities, but prevent vehicle intrusion as well.
Infrastructure and lifelines. Providing power, gas, water, wastewater, and communications services is one of the most basic requirements of any school development. At the site scale, all critical lifelines should have at least one layer of redundancy, or backup. By eliminating single-point vulnerabilities, designers will reduce the chance that service will be interrupted if an attack damages or destroys a lifeline either outside the school perimeter or on site. It is important to note that collocating a backup lifeline with its primary lifeline does not eliminate single-point vulnerability; only physical separation can substantially increase the likelihood of continuity of service.
Additionally, all controls, interconnections, exposed lines, and other vulnerable elements of school infrastructure systems should be protected from access and exploitation by surveillance and/or physical countermeasures. Service entrances and other secondary access points should be monitored and access-controlled; special attention should also be paid to any locations where multiple systems or primary and backup systems come together, such as control rooms and mechanical spaces. Again, these facilities should be designed
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