Aluminum is commonly used on the exterior of a window, generally to clad a wood window. It is very resistant to impact and extreme weather and thus is used extensively in areas prone to high winds and tropical storms. Marvin Coastline windows and doors, for example, are completely made of extruded aluminum for strength to withstand hurricane winds. Aluminum is low-maintenance and resistant to color fading and degradation. Look for aluminum cladding that is extruded into finished profiles in the manufacturing process. Extruded aluminum is thicker than roll-form aluminum and performs better.