Analysis of information sources in references of the Wikipedia article "Window" in English language version.
The casual, spread-out ranch house [...] by 1950 accounted for nine out of ten new houses. [...] Its one extravagance was a large window facing the street - the picture window. As far as I have been able to determine, picture windows made their first appearance in Levittown, Pennsylvania.
In general two or three windows united in a group, as was later the rule in Roman architecture, were even then of frequent occurrence in the early Christian architecture of Asia Minor. The form of the window is nearly everywhere the same; a rectangle that usually has a rounded top, but seldom a straight lintel.
The place of the window was determined by the architectural membering of the basilica, the distance between two columns generally indicating the position of a window.
