In general, the focus of code changes and design initiatives has been on how to harden buildings against structural damage that might be caused by blasts or fire and how to facilitate evacuation and emergency response.
"All of the effort seems to be going toward the physical structure," says James Woods of the Building Diagnostics Research Center, who also chaired the American Society of Heating, Refrigerating, and Air-Conditioning Engineers' ad hoc Committee on Building Health and Safety under Extraordinary Incidents. "As far as protection against chemical, biological, and radiological, not so much."
That's a mistake, Woods contends, because infection control is viable. Biological labs have those measures in place already, he says. And companies such as U.S. Global Aerospace manufacture HVAC "nanofilters" that capture minute agents such as anthrax.
Countermeasures that could be designed into a structure include sensor technology--for early detection--and better design and use of HVAC systems and filters to reduce the spread of toxic agents, says Woods.
Scientists at the Georgia Institute of Technology are working on chemical and biological sensors that can be built into ventilation systems. Upon sensing a harmful agent, the sensor could trigger a shutdown of the system.
A few building designers and engineers are also addressing this threat, says fire expert Dunn. Instead of central air conditioning, for example, they have designed some buildings with air conditioning systems--and ductwork--that is segmented by zones that cover just one or two floors instead of 10 or 20.
Central-air systems that serve many floors have shaftways and duct systems that penetrate fire-rated walls, floors, partitions, and ceilings. Extra air systems drive up the cost, but they also potentially limit the spread of toxic agents or smoke.
Another way in which some building designers are going beyond hardening of the structure to reduce the terrorist threat is by adapting their own version of crime prevention through environmental design (CPTED). The concept might be called antiterrorism through environmental design.
The objective is to lay out a new building to facilitate, rather than fight with, security's access control needs, limit injuries from attacks that do occur, and allow for quick evacuation in an emergency. Ron Couch, Stanley Security Solutions' chief operating officer for security integration, says that he is educating architectural and engineering groups on designing buildings with these CPTED-related principles in mind to enhance security.
In New York, says Galioto, new buildings are designed with these principles in mind. Architects, designers, and engineers consider occupant evacuation, checkpoints for delivery people, and mailroom sites early in the design phase, he reports. For example, lobbies sometimes must accommodate larger reception desks for package and briefcase screening.
With the exception of the major metropolitan areas, especially New York and Chicago, action to incorporate the lessons of 9-11 into future buildings is virtually nil, says Jon Magnusson, an engineer who sits on the NFPA High Rise Building Safety Advisory Committee.
The reason for inaction is not hard to ascertain: "The risk is perceived to be relatively low," says Woods. In addition, outside of the cities that take the risk seriously, awareness of the changing standards is also very low.
Architect Nadel speaks around the country about changes made to the New York building code. "I get the real impression that architects, engineers, and design professionals are totally unaware" of those changes, she says.
Woods has likewise crisscrossed the country talking about these issues. He too finds that interest in further protecting buildings "is just not there."
That may be a mistake, cautions Nadel. She points out that the standard of care that courts will impose for building protection might be increasing as a result of the code changes.
"If it's out there and design professionals are changing best practices, then someone in another part of the country might be expected to know," Nadel warns. They are responsible for identifying these trends and conveying them to their clients, she says. Failing to do so could raise liability issues, although as yet there is no case law to show how courts view the issue.
Given that terrorism is still seen as a remote threat for most building owners, calls for better building designs, such as those forthcoming from NIST, may continue to fall on unreceptive ears. But, notes Nadel, companies do understand the threat posed by natural disasters. "If we can get their attention dealing with that, they might deal with some of the terrorism issues."