A building element (E) is used for building walls, partitions, plates or closing devices such as blinds and doors, in particular for buildings and includes at least one volume (3) in particular in the form of a prism or cylinder limited by first (1) and second (2) faces made of a transparent material and sidewalls (4), wherein the element (E) includes at least one lens (5) which contains a focal plane and is placed near the first face (1) and a translucent screen (7) placed between the lens (5) and the second face (2). The image of a space in front of the lens (5) is formed on the screen 7 and can be seen from the rear of the building element (E).