Abstract: A unique thermal barrier is provided for use with a window in a building construction. The thermal barrier comprises a sheet at least the same size and preferably somewhat larger than the size of the window and one edge of the sheet is secured to the building above the window. A plurality of slats are secured to one side of the sheet so that the slats extend substantially horizontally and are parallel and adjacent to each other. In addition, the slats are constructed of a thermal insulating material such as a polystyrene foam. A decorative covering is also secured to the sheet so that the slats are positioned in between the decorative covering and the sheet. In addition, a cord is operable to move the sheet with its attached slats between a lower position, in which the sheet covers the window opening, and an upper position in which the slats are folded upon each other thus exposing a substantial portion of the window opening.