An office tower with brains

With 85 percent of the nation's office buildings in private hands and a spaghetti snarl of local and state building codes, no federal mandate can make all of America's buildings disaster-proof. But architects and engineers are creating a new generation of "smart" offices that not only keep intruders out but protect occupants from chemical and biological attacks.

Central air

Sensors wirelessly connect to control boxes that isolate affected areas and begin pumping clean air into the building.

Escape plan

Alerts trigger an automated evacuation plan that directs occupants to uncontami-
nated areas along lit corridors.

Toxin scouts

Sensors posted on rooftops or in air vents detect toxic substances such as anthrax.

Biometric scans

Iris-scan systems and spycams protect the lobby from intruders.

Oxygen

Control center

Digital escape planner