rooms that are fully partitioned and have individual air supply or 100 percent air exhaustion (such as in hospitals and hotels). Spaces designed specifically for large assemblies of people are different from the open floor plan because assembly spaces are equipped to control the indoor environment for large group gatherings. All of these space types can be combined in one building—for example, a school building with several classrooms, open-space cafeterias, and an auditorium. Protection strategies for each of these building types likely vary with the building’s mission. The ability to achieve different levels of protection depends on the building type. A highly cellular building has a reduced risk of exposing a large number of occupants to a threat agent in the event of an interior release because the threat agent can remain localized.
The need to protect a building from different threat types is driven by its mission and operations. To design an appropriate system, the goals of protection must be defined first, and the factors that limit its design and implementation (for example, building procurement and type, costs) have to be considered. Grouping of threats helps to determine the level of protection needed and the necessary components in the protection scheme to achieve that level of protection.