Rainscreen cladding is one form of weather cladding: it is designed to protect against the elements, but also offers thermal insulation. The cladding does not need, itself, to be waterproof, merely a control element: it may serve only to direct water or wind safely away in order to control run-off and prevent its infiltration into the building structure. Cladding may also be a control element for noise: whether entering or escaping. Cladding applied to windows is often referred to as window capping and is a specialized field.