When someone describes a beautiful building in the city, in all likelihood, they are describing the building's façade—that thin, skin-like layer of brick, mortar and/or decorative stone such as limestone that covers and dresses up the raw, inner walls of the building. Although one of the purposes of a building's façade is decorative, façades serve a much more vital role than just window dressing for a building's exterior.
The façade of a building and the human skin serve nearly identical purposes. Our skin serves as a decorative layer, giving us recognizable features. More importantly, however, skin serves as a protective layer keeping harmful UV rays, water, pollution, extreme temperatures, bacteria, dirt and foreign matter from infiltrating and harming our bodies.
In essence, the façade of a building does the exact same thing. It protects a building's inner walls from the harsh elements, dirt and pollution a building has to endure over time. Unlike skin, however, building façades are built using a variety of materials.
"The façade of a building keeps the rain and cold temperatures out and the heat in," says Andrew Wist, president and CEO of AA Standard Waterproofing in the Bronx. "It serves as an insulator for the building. Without a façade, you do not have a front to the building," he adds. "Many different materials can be used when building façades. The most common is brick of course. But you also see limestone, other types of decorative stone such as terra cotta."
Howard Zimmerman, owner and principal of Howard Zimmerman Architects PC in Manhattan concurs. "The façade of a building is its first line of defense. It is a raincoat for the building. It keeps the elements out and insulates, while at the same time serving a decorative purpose."