The term originated from an Italian word, which means 'ledge'. They can be modified to suit your individual needs and can also be custom created. The structure will vary according to its intended use.
Exterior cornices generally focus on functionality, but can also work to a decorative advantage. By using different architectural styles, you can make them work like a 'crown' for your building.
For obvious reasons, they are made from materials like reinforced fiberglass that will withstand the elements. Such materials are low maintenance and are available in a number of finishes, which can be modified to suit the building they are used for.
Exterior cornices are essential architectural elements that offer some amount of protection from the damaging effects of excessive rain, snow, or sun. It's a good idea to ensure that they have a slight slope away from your building to prevent rainwater from stagnating on them.
As is the case of practically everything in the world today, cornice designs can be custom created. You can highlight them by adding coordinated décor elements, like wallpaper and fabric, and get the cornice customized to your dimensions and textures. Customizing is an expensive option, it can add style, substance, and finish to an otherwise ordinary room.
Cornices are easy to overlook in the grand scheme of things. However, with some good designs, you'll be glad you took the time to pay attention to them!