How Building Sciences Have Changed Since 9/11
Friday, September 9, 2011
As the nation prepares for the tenth anniversary of September 11, 2001, the National Institute of Building Sciences reflects on how building sciences have changed over the past decade.
Since that tragic day, the Institute has worked with federal agencies and the building industry to improve the safety, security and resilience of the nation’s buildings.
Following the completion of the National Institute of Standards and Technology (NIST) World Trade Center investigation, the National Institute of Building Sciences Multihazard Mitigation Council (MMC) convened a diverse group of experts that worked with NIST to translate the investigation’s recommendations and develop consensus proposed changes to national building and fire codes.
The MMC successfully shepherded several code change proposals related to the WTC recommendations through the code development process and served as a focal point for advice on WTC-related codes and standards change proposals. There have been as many as 40 major changes to the model codes and 15 changes to key standards. These changes were based on recommendations from the NIST World Trade Center investigation.
"The building construction and regulatory systems have had to rethink the very difficult questions of, How safe is safe? and, How large an earthquake, flood or hurricane should we design for?" said Gerald H. Jones, PE, co-chair of the committee.
Since late 2003, the Institute has continued to work closely with NIST and other federal agencies to develop state-of-the-art guidance for the prevention of progressive collapse in new and existing buildings and for assessing the vulnerability of buildings subject to threats.
"The speed, magnitude and scope of the changes to building and fire codes, standards and practices in response to or consistent with the recommendations of the WTC investigation have been truly remarkable," said Dr. Shyam Sunder, Sc.D., Director, Engineering Laboratory at NIST. "Beyond changes to model codes and regulations, the industry itself has made significant advances in practice to improve the robustness and resilience of tall buildings [including 1 World Trade Center, 7 World Trade Center, buildings in the Asia-Pacific region and the Middle East.] The robustness and resilience will improve response…through better occupant evacuation, emergency responder access, fire protection and structural systems."
Since 9/11, the U.S. Department of Homeland Security (DHS) has worked on ways to quickly and reliably assess the vulnerability of our nation’s critical infrastructure. The DHS Science and Technology (S&T) Directorate’s Infrastructure Protection and Disaster Management Division (IDD) has developed a unique set of Integrated Rapid Visual Screening (IRVS) tools for buildings, tunnels and mass transit stations.
The new IRVS screening tools provide a quantification of resilience and risk and assessment of explosive, chemical, biological and radiological attacks; earthquakes, floods and high-wind hazards; and fire hazards. The results are especially useful for identifying a specific asset for more detailed study and developing mitigation measures that will reduce the risk ratings.
The DHS S&T IDD also developed the Security Information Technologies Exchange (SITE) to provide quick access to critical security information needed by building designers, owners and security specialists. The National Institute of Building Sciences manages this searchable, online database of security products that meet the federal Interagency Security Criteria (ISC), U.S. Department of Defense (DoD) security standards and U.S. Department of Veterans Affairs (VA) security criteria. Products in the SITE database range from blast resistant windows and films to intrusion detection systems; from vehicle barriers to access control systems; and ballistic resistant wall systems to personnel screening. SITE also will include products certified to the DHS Safety Act.
In response to the events of 9/11, VA recognized the need to develop criteria to provide physical security for healthcare facilities. No other federal agency had undertaken the tasks of understanding and developing methodology to keep mission-critical healthcare facilities operational during a national emergency.
VA developed a methodology intended to employ a flexible and realistic approach to the reliability, safety and security of federal, state and local governmental and private sector facilities. The Federal Emergency Management Agency (FEMA) 426 Reference Manual to Mitigate Potential Terrorist Attacks Against Buildings relies heavily on the methodology developed by VA and on DoD Standards for their evaluation of federal and private sector facilities in terms of the identification of vulnerabilities and recommendations of mitigation strategies. FEMA 452 Risk Assessment: A How-To Guide to Mitigate Potential Terrorist Attacks Against Buildings utilizes the methodology developed by VA and distributes (with VA permission) the software developed during VA’s project to assess facilities and compile data for analysis.
VA chose a multi-hazard approach to physical security planning, design and construction. The Department has taken appropriate actions to enhance the readiness of VA medical centers to protect the patients and staff from chemical or biological attack or otherwise to respond to such an attack so as to enable such centers to fulfill their obligations as part of the federal response to public health emergencies, which includes serving as a back up to DoD medical services and supporting the National Disaster Medical System during national emergencies. VA also furnishes hospital care and medical services to individuals responding to, involved in, or otherwise affected by that disaster or emergency.
Since 2002, the Institute has directed a major security assessment program for the VA that performed security assessments of more than 200 VA medical centers using a team of over 20 consulting architects, engineers and security experts. As part of this program, a methodology was developed and automated, which has been published and distributed to the public through DHS and FEMA and serves as the basis for the DHS IRVS used by a number of federal agencies, including the Transportation Security Administration (TSA).
The construction teams responsible for rebuilding the facilities at the World Trade Center site and the Pentagon have used new technology—building information modeling (BIM), analysis and simulation—during the construction process. (The buildingSMART alliance, a council of the Institute, is the developer of the National BIM Standard-United StatesTM.)
A BIM of the Pentagon helped with damage assessment and rebuilding efforts there. Model-based scheduling was used extensively to deliver the Pentagon reconstruction. BIM also was utilized to coordinate the many independent aspects of the work at the World Trade Center site. BIM helped to ensure the optimum use of materials to protect against future incidences, as well as faster delivery of facilities, often at lower cost than traditional methods.
While much of the past decade’s focus has been in measuring resistance to man-caused threats, a number of recent events remind us of the need to assess buildings and structures against natural disasters as well. As identified in MMC’s 2005 study, "Natural Hazard Mitigation Saves: An Independent Study to Assess the Future Savings from Mitigation Activities," $1 spent on mitigation saves society an average of $4. The MMC continues to promote increased all-hazard (man-caused and natural) disaster resilience in homes and commercial buildings as part of a whole building strategy that incorporates sustainability, security and use of GIS and other technological tools. This expansive approach will be directed to homeowners, businesses, schools, communities, public and private sector building portfolio managers, and many others.
In summary, the National Institute of Building Sciences has supported federal agencies in a number of activities to ensure the safety, security and resilience of the nation’s buildings and will continue its efforts to improve America’s buildings in the years to come.