Windows Casement Casements open at the side and seal tightly to the frame. Awnings Awnings open from the bottom out for optimal ventilation in a variety of weather conditions. Double Hungs Double hungs have two moving sash that slide vertically to open and close. Single Hungs Single hungs have a stationary top sash and a bottom sash that slides vertically to open. Sliders Sliders have sash that slide horizontally from side-to-side. Folding Windows Expansive folding windows are available in numerous configurations to merge the indoors and out. Tilt-Turns This classic style opens two ways: it swings in at the side or tilts open at the top for extra ventilation. Bays Flank a center window with gently angled double-hung or casement windows. Radius Stack half-circle or elliptical windows over other Kolbe windows, or use circular units to illuminate cozy spaces. Geometric Custom shapes such as triangles, trapezoids, octagons and pentagons add visual dimension, either alone or in conjunction with other types of windows. Direct Sets Direct sets are designed with glass set directly into the frame for areas that do not require operating windows.