The windows have stone surrounds, mullions and transoms. Horizontal transoms sometimes had to be introduced to strengthen the vertical mullions. The windows are divided into segments by stone mullions and tracery. This corrosion bowed the horizontal mullions and broke most of the spandrel glass panels. The construction includes Guiting Yellow stone and some Jacobean mullions and gables. The entrance features three vertical window bays with decorative aluminum mullions. Raymond used precast concrete to form decorative elements for the building, such as window mullions. Windows are plain openings without trim or mullions. During the 1970s, the widespread use of aluminium extrusions for mullions began. Stainless steel rods make up the window mullions. "Infill" refers to the large panels that are inserted into the curtain wall between mullions. Two of the facade's mullions support a large central clock. This allowed for the introduction of more transparent glass with minimal structurally glazed mullions. Deflection in mullions is controlled by different shapes and depths of curtain wall members. In some cases, anodizing may protect thicker aluminum, such as aluminum window system mullions.