Designed by the American architects Frank Furness and George Hewitt, it has been called "One of the most magnificent Victorian buildings in the country."[1] The building's facade draws from a number of different historical styles, including Second Empire, Renaissance Revival and Gothic Revival, amalgamated in an "aggressively personal manner".[6] The building's exterior coloration combines "rusticated brownstone, dressed sandstone, polished pink granite, red pressed brick, and purplish terra-cotta."[6]