| It is hard to believe that design professionals are still designing large buildings that may be hazardous to their occupant’s health. It has been more than ten years since a concealed bomb within a rental truck exploded outside the Alfred R. Murrah Federal Building in Oklahoma City, Oklahoma, killing 168 people on April 19, 1995. Years later, the World Trade Center disaster reinforced for engineers and architects the concept that terrorist-resistant construction could save lives. Such principles should be strongly considered when designing a new building or before retrofitting an older building.
We have little influence over terrorist target selections, but we can directly influence building designs that better protect people and other assets. This holds true whether we are speaking of “at risk” structures, such as government facilities, or “standard” buildings.
When considering security design, it is important to keep in mind what uses are intended for the building. Security designs and retrofits that increase security through technology while disrupting workflow and hindering productivity should be avoided. The goal for any building designer should be to facilitate security and safety interests by recognizing security access control needs, limiting injuries from natural or manmade disasters and allowing for rapid evacuations during emergencies.
Numerous guidelines have been promulgated by various organizations over the past few years; however, these guidelines have not made it into local building codes. Issues ranging from air-filtration, blast resistant construction, structural member strengthening and other security improvements often continue to be neglected.
Ways to Make Buildings Safer
What security-related areas should be considered in new building design or construction? The short answer is everything—from the parking lot location, lighting, which way the building faces, the number of entrances, and landscaping, to the construction materials used. These and other building features can make a significant difference in how a building can better protect its occupants. For example:
• Glass Treatment. In an explosion, flying glass causes the majority of injuries and deaths. Thus, the most significant life-saving measure that can be employed is protecting occupants and passers-by from flying glass. This can be accomplished through window treatments (normally by placing a special polymer between two layers of glass) and reinforcing the window frame to prevent the glass from flying out of its frame. A less costly alternative involves the application of Mylar1 film to existing windows.
• Exterior Walls. Technological advances now allow us to reinforce exterior building walls by applying a carbon fabric glued to a layer of Kevlar2. A few inches of this reinforcing product is equivalent to five feet of reinforced concrete.
• Columns. Support columns are strengthened through the use of a thick wallpaper-like fabric that prevents concrete columns from cracking and crumbling from an explosion at close range.
• Air Intakes. Locating air intakes at upper floor levels reduces their vulnerability to tampering, and adding filters that capture particles larger than 0.3 microns reduces the possibility of occupants breathing in potentially harmful materials.
• Sensors. Technology can now provide early detection of toxic substances. In addition, air handling systems that are segmented by zones reduce the spread of potential contaminates.
• Showers. Installing outside showers for decontamination purposes restricts the spread of contamination to building interiors.
• Mailrooms. Locations of mailrooms should be considered early in the design because they can be critical attack points (package bombs, contamination, etc).
• Access. Vehicle barriers and checkpoints limit facility access to screened personnel.
Other areas to consider in improving security design include reducing the number of access points, relocating parking lots further from buildings to increase stand-off distances, increasing lighting, installing an access control system and/or security cameras, protecting utilities and HVAC systems, reducing the size and/or quantity of windows, and ensuring that alternate power sources are available for emergencies.
Further design efforts should also be directed at making structures safer for occupants during emergencies. Such efforts may be best directed to the following areas:
• Elevators/Stairs. Fully encase elevators and stairs in a reinforced concrete core and/or locate fire stairs at opposite ends of the building. Consider widening stair width to help with evacuation and provide space for the counter flow of emergency responders.
• Fireproofing. Spray-on fireproofing coating materials should be specified for critical structural members.
• Exit Lighting. Use emergency exit lighting similar to that found on airlines to direct building occupants to exits. Consider also the addition of photo luminescent or electroluminescent strips on emergency exits and exit stairs.
• Open-web steel joists. These types of joists should be reconsidered for use in non-residential high-rise buildings because they have too little surface area for adequate spray-on fireproofing applications.
Cost of Designing Safer Buildings
Certainly, a hot topic in any discussion concerning security design or enhancements includes that four-letter word, cost. It is true that the cost of security is a significant factor in most projects; however, costs can be significantly reduced if appropriate security design is incorporated in the early stages of a project. Rough cost estimates to design and incorporate security within original building designs are about 5 percent of total building cost. This figure is considerably higher for designing a security retrofit and incorporating security into older buildings. Often, a wise use of limited security dollars is to reinforce columns, walls, windows, and floors; add special filters to HVAC systems; install vehicle barriers; and provide landscaping such as earthen berms.
All of these methods reduce terrorist threats considerably. Employing even one of them enhances a building’s security; although applying multiple protective measures simultaneously often increases the security and safety benefit more than any measure applied singly.
PB’s Homeland Security Group
PB’s Homeland Security Solutions Group focuses on protecting all types of critical infrastructure and has been in operation since before the 2000 Salt Lake City Olympics (one of their first efforts). Common services include vulnerability and risk assessments of facilities and recommending and designing physical security countermeasures. Recent security work includes security assessments of the 20 largest U.S. transportation systems, extensive work with the Port Authority of New York and New Jersey (PANY/NJ), national critical bridge assessments, cruise ship security efforts on east/west coasts, security upgrades to government buildings (in classified and unclassified environments), work for the Center for National Response and national/international port security efforts under the Maritime Transportation Security Act (MTSA) and the International Ship & Port Facility Security Code (ISPS). |
