United States federal building security

A variety of measures are undertaken to make the buildings safer, while preserving an open architecture consistent with democratic governance.

This includes glass glazing to reduce the potential for injuries from shattering glass; greater standoff distances implemented by preventing unscreened traffic from approaching within a certain distance of the building; and measures to prevent progressive collapse of buildings.

[1] These buildings contain mission functions critical to national security, such as the Pentagon, CIA Headquarters, and ARTCCs.

This type of building has 450 or more federal employees; high volume of public contact; more than 150,000 square feet (14,000 m2) of space; and tenant agencies that may include high-risk law enforcement and intelligence agencies (e.g., ATF, FBI, and DEA), the Federal courts, and judicial offices, and highly sensitive government records.

This type of building has 10 or fewer federal employees; low volume of public contact or contact with only a small segment of the population; and 2,500 or less square feet of space, such as a small store front type of operation.