Abstract: A window construction is provided having a window frame with horizontal top and bottom members extending between vertical side members. The horizontal members define surfaces that slant downwardly and outwardly with respect to the frame at a predetermined angle. Window units are positioned within the frame and each unit includes a sash having horizontal elements extending between vertical side elements. The horizontal elements of each window unit define surfaces that slant downwardly and outwardly with respect to the frame at said predetermined angle. When in place, the slanting surfaces of the window units contact the slanting surfaces of the window frame to provide a weathertight seal. Fastening means are provided to enable each window unit to be individually placed into position within and removed from the frame.