‘Curtain wall’ is a term generally applied to vertical, external elements of a building which are designed to protect the occupants and structure of that building from the effects of the external environment. Whilst keeping out the wind and rain, a curtain wall can also provide a multitude of different options related to appearance and functionality. The external surface of a curtain wall might be 100% glass or might include other cladding materials such as stone and aluminium panels. A curtain wall may contain specific architectural features designed to enhance the appearance of the building or elements intended to manage the effects of the environment. Such features may include brise soleil and external fins designed to provide shading or photo-voltaic panels capable of generating electricity. A modern curtain wall will be designed as a cladding element rather than a structural member and as such the removal or failure of an element or section of the curtain wall will not result in disproportionate damage to the structure.