Wall openings are modest in size and recessed in response to the high altitude sun and accompanying glare. Configuration is generally vertical rectangles, but small rounds or squares can be found. Windows are set with divided panes and glazing is clear or light gray, never color tinted. Some pairing is seen, but a series of joined windows are not. Limestone surrounds are common, but heads and sills of sandstone are also evident. The preferred window frame material is steel and always black, or close to it.