505 Montgomery Street is a 24-storey, 100m class-A office building in the financial district of San Francisco, California. The 98ft spire perched atop the building is thought to be a replica of the Empire State Building, but that association is mainly due to the publicity stunt during the opening of the building, which involved an inflatable 40ft gorilla perched on the spire.History505 Montgomery was developed by the Empire Group of San Francisco. Empire assembled ten contiguous parcels in 1978, and filed their initial design study on with the San Francisco Department of City Planning. The initial design called for a 28-story building, high including a 16ft mechanical penthouse and ground-floor commercial space. The design was revised to a 24-story building based on floor area ratio calculations, and the final conditional use authorization was granted in June 1984. During construction, Mitsui Fudosan acquired a controlling interest in the unfinished building from The Empire Group and development was completed under the management of AMB.Retrofitting projects, including a 1994 lighting retrofit, earned the building an Energy Star label. National Office Partners (NOP), a partnership between Hines Interests LP and CalPERS, acquired 505 Montgomery from Mitsui Fudosan and The Empire Group in 1999. The building was subsequently sold by NOP to RREEF in 2005.
