Abstract: Energy efficient window and skylight assemblies having self-contained ventilating systems. Two sheets of a transparent or translucent material are spaced apart in parallel relationship so as to form an air flow channel between the sheets. An adjustable shade is positioned in the air flow channel to regulate the amount of sunlight passing through the window and skylight assemblies. A fan in the top or bottom of the assembly causes air to be drawn into the assembly and passed through the air flow channel where it absorbs heat from the shade and sides of the assembly. This air is then directed into the building to provide heat or is vented to the outside to decrease the heat gain in the building.