The building was designed in the Beaux Arts style, with elements of the City Beautiful Movement. The City-County building is a representation of a distinctly American extrapolation of the Beaux Arts mode. Hornbostel was known for this architectural style, and architectural historian James Van Trump has stated that Hornbostel kept the principles of the Beaux Arts central with his designs, but also frequently departed from the precepts, and integrated elements of other styles akin to industrially-inspired brutalism. The design of the building was also influenced by the City Beautiful Movement. This movement featured urban planning with soaring Neoclassical buildings, clean and orderly designs, and included the concept of the “White City”. The City-County Building was one of Pittsburgh's first attempts at incorporating the City Beautiful Movement into its urban design.