The curtain wall or curtain wall is a particular type of continuous light envelope, which guarantees all the normal functions of an external wall. Curtain walls are today typically designed with an extruded aluminum structure, although a niche for special applications is represented by the steel structures for the physical and mechanical characteristics that guarantee wider spans.
The metal structure of uprights and transoms is generally filled with glass, which provides excellent architectural performance, as well as benefits for light and environmental control.