Building cladding is one of the most expressive, inspiring, and complex aspects of architectural design. The primary function of a building's or structure's envelope or enclosure is to protect the covered or otherwise conditioned interior spaces from the surrounding environment. The building's outward appearance, including the facade and cladding, determines how well it is perceived by onlookers. Environments that are innovative and well-structured always receive positive feedback. The facade is the skin of a building, whereas the cladding is the makeup of the architecture. Metal facades and cladding are arguably the most desired material for modern architecture. As a result, the use of metal facades and claddings helps to drive this innovation.