The Pentagon: Construction
began: September 11, 1941 Construction completed: January 15, 1943 Complex: 34 acres: building covers 29 acres; inner courtyard covers 5
acres; Dimensions: 77 feet high; each wall is 921 feet long; Walls: 24 inches thick - 6 inches of Indiana limestone; 8 inches of brick;
10 inches of concrete Space: 3,705,793 square feet of office space on five floors; 17.5 miles
of corridors; Elevators: 13 Escalators: 19 Stairways: 131 Workers: 23,000
The Pentagon is constructed in five concentric rings connected by ten spoke-like
corridors. It is in the midst of its first renovation since its construction
in 1941. The extensive renovation began in 1998.
The renovated sections included new designs to minimize the damage from an explosion: 1. Steel Beams were installed on each side of every exterior window 2. A strong mesh material, similar to Kevlar, was stretched between the
beams to catch flying debris. 3. New blast-resistant windows were installed. The panes were an inch
and a half thick and each window weighs 1,600 pounds.
