As the names imply, fixed awnings are frozen into a single position, while retractable awnings can be opened, closed, or stopped at any point in between. This ability to move an awning gives retractable awnings significant flexibility, and this flexibility translates into some significant performance benefits.
An awning or overhang is a secondary covering attached to the exterior wall of a building. It is typically composed of canvas woven of acrylic, sunbrella fabrics, cotton or polyester yarn, dickson, or vinyl laminated to polyester fabric that is stretched tightly over a light structure of aluminium, iron or steel, possibly wood or transparent material (used to cover solar thermal panels in the summer, but that must allow as much light as possible in the winter). The configuration of this structure is something of a truss, space frame or planar frame. Awnings are also often constructed of aluminum understucture with aluminum sheeting. These aluminum awnings are often used when a fabric awning is not a practical application where rain load as well as wind loads may be a factor.
