Abstract: A solar heated building comprising a frame, an inner wall supported by the frame, and an outer wall of generally transparent material supported by the frame and spaced outwardly of said inner wall thereby defining a passage therebetween. The passage has an inlet for the flow of air into the passage and an outlet in communication with the interior of the building for flow of air from the passage into the interior of the building. The inner and outer walls are positioned for incidence thereon of solar radiant energy, whereby on flow of air through the passage the air may be heated by the solar radiant energy prior to flowing into the interior of the building.