Small windows called "basement hopper windows" are put in basements to let in more light as well as some air circulation. They open at the top and are hinged at the bottom. Basement hopper windows seem to be able to be opened and let in the sunshine, apart from glass block windows.
At least 24 inches must be present in the opening height. At least 20 inches must separate the openings. The window must have glass that covers at least 8% of the floor area of the room in order to let in the minimum amount of natural light necessary.
