What state has the largest office building?
The Pentagon is d world largest office building by floor area with about 6500000 sq ft (600000m2). It was built in September 11, 1941-January 15, 1943. Built by John Mc Shain. Inc. Five floors above ground and two floors below the ground (estimated).
Texas has the largest state capitol building. The original building itself has 360,000 square feet of floor area, more than any other state capitol building, but the 1993 extension, which was built underground so as to preserve the original building's architecture, adds 667,000 square feet of floor space. There is a link below to a source article.