Retractable solar window awnings are made from fabric. They are resistant to hail and harsh winter weather. Many solar window awnings can be programmed to open and close automatically in response to the sun.
Because the canvas remained attached to the framework, retractable awnings allowed a more flexible approach to shading (shopkeepers and owners could incrementally adjust the amount of awning coverage depending upon the weather conditions). When the sun came out from behind clouds, the awning could be deployed with ease. In case of sudden storms, owners could quickly retract the awning against the building wall where it was protected from wind gusts.
Awnings became common during the first half of the 19th century. At that time they consisted of timber or cast iron posts set along the sidewalk edge and linked by a front cross bar. To lend support to larger installations, angled rafters linked the front cross bar to the building facade. The upper end of the canvas was connected to the facade with nails, with grommets and hooks, or by lacing the canvas to a head rod bolted to the facade.
Among the most significant awnings in the ancient world was the velarium, the massive complex of retractable shade structures that could be deployed above the seating areas of the Roman Colosseum. Made of linen shadecloths, timber framing, iron sockets and rope, the system could effectively shade about one-third of the arena and seating; another third could be shaded by the high surrounding walls, providing a majority of seats some shade on a blinding afternoon. It is believed that sailors, with their background in sailmaking and rigging were employed to build, maintain and operate the velarium.