A window frame of extruded material having vertical members including sash guides wherein the vertical members are identical but reversed with respect to each other and in mirror-image relation; the sill and header are identical but inverted and reversed end for end with respect to each other. Each frame may be constructed of an identical pair each of two different members. The sill slopes downwardly toward the exterior of the frame. The sill and header are notched at right angles to the outer and inner surfaces to form corner seams which carry out the horizontal lines of the window frame and which do not require exact and difficult mitering to obtain a perfect seam. Such joints do not open during shipping and handling as do miter joints. The sash frame elements are made from a third extrusion. The vertical members and the sill and header are provided with sash supports in which the outer sash edge rides against an end wall of a vertical channel which faces into the window. The inner sash rides against the side of the same channel wall thereby bringing the sashes close together. The header and sill each have a horizontal channel; the sill channel matches the end of the vertical channel wall against which the upper and outer sash rides and the side of the vertical channel against which the inner and lower sash rides to provide means for weather exclusion.
