Abstract: A structural support assembly and its method of formation for collecting solar energy, regulating heat gain and loss, controlling light transmission and being adapted to be interconnected with other structural elements to form a building. The support system includes an elongated rigid support member having opposing side walls and a base. At least a portion of each side wall is formed of glass. A solar collector assembly is associated with one of the side walls, preferably one to be at a generally southern exposure when incorporated in a building in northern latitudes and vice versa in southern latitude and being positioned to maximize solar gain. An adjustable light weight insulating panel is provided and is positioned with respect to the other of the sides, preferably one to be at a generally northern exposure in northern latitudes and vice versa in southern latitudes when incorporated in a building, and being adjustable to regulate the light received and heat lost or gained through the other side.