The Clement F. Haynsworth, Jr. Federal Building in Greenville, SC is of simple Greek Revival style. The main entry to the building is on the north elevation. In the center of the north elevation is a projecting central temple front with a classical pediment supported by six square Tuscan columns. The portico formed by these columns has a quarry tile floor with wrought iron balcony rail at the 2nd floor level. The three main entry doors are at the first floor level in this bay. The entry doors are surrounded by verde marble. The original wood entry doors have been replaced by decorative metal ones but the original bronze transoms over each door remain in place. The original bronze wall mounted sconces still flank the main entries. The sconces have an octagonal frame with grille work over opaque glass. Atop the sconce is a winged upright eagle sitting on a sphere mounted on a fretwork pedestal. Underneath each sconce are bronze letters. On the east side the letters read "UNITED STATES COURT HOUSE"; on the west, "UNITED STATES POST OFFICE". Above the main entry are bronze letters reading "CLEMENT F. HAYNSWORTH, JR. FEDERAL BUILDING".
At the south elevation the interior plan of the building becomes apparent. A light court is formed by the projecting east and west wings. In the center of the light court is a central projecting pavilion topped by a simple Classical pediment. The loading dock originally opened off the 1st floor level. Currently the 1st floor loading dock is filled-in with limestone and the basement level opens to a parking lot. It is unclear when these changes were made.
The east and west elevations are simply finished but repeat the details of the other elevations. There are simple limestone bands at the second floor and cornice levels on all elevations. Each bank of windows is slightly recessed into the limestone. A simple panelled limestone spandrel panel with center block decorates each elevation between the 2nd and 3rd floor level windows.
First floor windows are 10/15 double hung wood windows. The 2nd and 3rd floor level windows are 10/10 double hung wood windows. All 2nd floor windows have been replaced with new wood Marvin windows. The windows are identical in outward appearance to the original wood ones.
The interior of the Haynsworth Federal Building has been changed considerably over the years. The main lobby was severely cut down in space by the addition of a wall running the length of the east-west corridor. The original bronze entry vestibule was removed and the current entry is blocked-off by the U.S. Marshal's security desk. The main staircases at the northeast and northwest maintain their original appearance though a new fire wall at each end of the lobby conceals them from view. The originally finished elevators at each floor with their bronze doors and marble surrounds enhance the appearance of the interior. Offices on the 1st and 2nd floor have been renovated several times over the years, though a small amount of original wood trim remains. At the time of inspection, all the 3rd floor offices were being renovated.
The original courtroom on the 3rd floor retains much of its original appearance.