Final answer:
A major horizontal division of a wall with no exterior windows is known as a spandrel or blind wall, often found in urban buildings to support structural loads or provide privacy.
Step-by-step explanation:
A major horizontal division of a wall having no exterior windows is often referred to as a spandrel or a blind wall. This feature can be seen in architecture where the wall space is required to support the building's structural loads or where privacy is needed, thus not allowing for windows. Such walls are particularly common in dense urban environments where adjacent buildings are close together, and they can sometimes be aesthetically treated with materials or artistic elements to prevent a monolithic appearance. For example, in historical buildings, spandrels might be decorated with frescoes or ornamental features to enhance their visual appeal.
The concept can be contrasted with the use of large windows and glass surfaces in modernist architecture where the intention is to let in as much natural light as possible, like the Chicago School window grid. Additionally, famous architectures like Fallingwater by Frank Lloyd Wright use large expanses of glass to harmonize with nature, starkly differing from the use of blind walls.