designed by architect charles bickel, the kaufmann's flagship store was built in 1887 at 400 fifth avenue in downtown pittsburgh. known as "the big store," it continued to undergo several expansions and renovations in later years. by 1916, the architects janssen & abbott designed a larger white terra cotta-sheathed addition that included a large public clock at the corner. in the late 1920s, edgar g. kaufmann commissioned a redesign of the main floor of the department store. local architect benno janssen and his partner william cocken rose to the challenge to complete the project. at one point, the building was the largest department store in pittsburgh with twelve retail floors, and spanning an entire downtown city block. it eventually reached 13 floors and covered 1.2 million square feet. kaufman commissioned frank lloyd wright to design his executive offices on the top floor of "the big store", as well as his country house 'fallingwater' (1934) at the company's bear run retreat in pennsylvania. the office interior was saved and reinstalled in the victoria and albert museum in london. he also commissioned architect richard neutra to design the desert kaufmann house (1946) in palm springs, california.