Architects have a number of choices when selecting architectural metal for roofing or siding based on the variety of design conditions in different building types. Many of those choices are rather energy intensive such as aluminum, copper, painted steel and stainless steel. However, zinc is emerging as an architectural metal of choice in the U.S. due in part to its comparatively low level of energy intensity and its widespread and long-term use in other parts of the world. Design professionals in European cities such as Paris, have specified zinc roofs since the late 1800s where the distinctive gray patina continues to crown over 80 percent of the rooftops there—some of which have been around for more than 100 years. Zinc building products, including roofing, wall cladding and rainwater systems, are thus enjoying new popularity in the U.S. due to recognition of its sustainability qualities and its long-lasting, low-maintenance benefits for owners.

Properties of Zinc

Zinc is a naturally occurring element (Zn is #30 on the periodic table) and a significant mineral that is prevalent throughout the world. In fact, it is reported to be the 23rd most abundant element in the earth's crust found not only in rocks, soil, air and water, but also in all living organisms including plants, animals and humans. Zinc is mined worldwide predominantly from extraction processes that avoid strip mining meaning that less land is disturbed and any potential environmental damage is minimized. Various projections have been made about the worldwide supply of zinc, but current estimates predict up to 750 years' worth of supply at current extraction levels. When recycling and reuse of zinc is considered, the projections are even longer.

Photo courtesy of VM Zinc Office building, Hoboken (Belgium) Designed by Sylvie Bruyninckx, Conix Architects