Abstract: The sash window assembly includes an upper sash window and a lower sash window. Each of these windows are mounted within opposed guide rails on a master frame. At least one of the windows is slidable within the frame relative to the other window. The window latch system includes a locking assembly for mounting on one side of the sash window. The locking assembly is designed to engage a keeper on the adjacent side of the other sash window. The locking assembly includes a housing having an extended hollow central shaft, an actuator arm, and a cam having a latching blade for engaging the keeper. Alignment pins or tabs are located on the bottom of the housing. A single retaining screw extends through the extended hollow central shaft and secures the housing to the window.

Abstract: A method and apparatus for installing a window assembly (10) is disclosed. The window assembly (10) includes a window frame (12), an upper (14), and an upper sash support (80). The window frame (12) includes two vertical jambs (18) and (20), a frame head (22), and a frame sill (24). The upper sash (14) includes two vertical stiles (26) and (28), an upper rail (30) and a lower rail (31). Each vertical stile (26) and (28) has an upper end and a lower end. At least one vertical stile (26) lower end has a web (41). The upper sash support (80) is adapted to receive the web (41) and support the upper sash (14). The method for installing a window assembly (10) in accordance with the present invention includes six steps.