Eleven inches could be a matter of life and death. So the designers of the new 7 World Trade Center, planned by Silverstein Properties, have called for fire stairs 66 inches wide, rather than the 55 inches specified by the New York code for such a building. They say that will allow room for two-way traffic: occupants going down and firefighters coming up. As one of the first office towers designed from scratch since the attack on New York, 7 World Trade Center is a 52-story laboratory of ideas about how extra safety measures can be incorporated into the fiber of a building. Full Story