Window awnings can reduce solar heat gain in the summer by up to 65% on south-facing windows and 77% on west-facing windows.
You can use an awning to shade one window or have an awning custom-made to shade the entire side of your house. Awnings can be fixed or retractable.
Awnings are made from synthetic fabrics such as acrylic and polyvinyl laminates that are water-repellent and treated to resist mildew and fading. Whatever the fabric, choose one that is opaque and tightly woven. A light-colored awning will reflect more sunlight.
Awnings require ventilation to keep hot air from becoming trapped around the window. Grommets (eyelets) or other openings along the tops and sides of an awning can provide ventilation. The awning may also open to the sides or top to vent hot air.
While awnings can save energy during the cooling seasons, they can increase energy used for heating, so keep this in mind when deciding whether awnings are right for you.
You can roll up adjustable or retractable awnings in the winter to let the sun warm the house. New hardware, such as lateral arms, makes the rolling up process quite easy. Some awnings can also be motorized for easy operation.
https://www.energy.gov/energysaver/energy-efficient-window-attachments