The 64 by 118-foot four-story addition was estimated to cost $150,000. Actually a separate building linked to the courthouse by a hyphen, it displays a restrained neoclassicism in pale stone, which contrasts with the robust eclectic style of the red brick courthouse designed by A. S. Eichberg. The portico and pilasters display the Tower of the Winds capitals popular in Wilmington and favored by Boney.