The variety of alloys utilized is spectacular: weathering steel for aging, marine-grade light weight aluminum for weight cost savings
https://storage.googleapis.com/metal-craftsmanship/serving-home-owners/uncategorized/the-honest-product-why-architects-count-on-copper-dormers-for-long-horizon.html
The series of alloys used is sensational: weathering steel for patina, marine-grade aluminum for weight savings, and duplex stainless for rust resistance in rough environments.