Abstract: A snap fitted dual frame window assembly provides for convenient installation of a window in a basement foundation of a residential home. An outer frame is used as a form or spacer for the window during pouring of a concrete foundation wall and has a sloping recessed guiding wall to accommodate an inner vinyl frame. Vinyl frame clips are attached to the inside of the outer frame to secure the inner vinyl frame. The inner vinyl frame includes a channel section which can be forced over the frame clips and then is held, in a snap fit, by the frame clips. One arm of a hinged window sash is mounted on the inner frame and the other is mounted on a window frame. The inner frame can be easily removed from the outer frame and re-installed in different orientations.